[Federal Register Volume 75, Number 156 (Friday, August 13, 2010)]
[Notices]
[Pages 49710-49758]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-19950]
[[Page 49709]]
-----------------------------------------------------------------------
Part V
Department of Commerce
-----------------------------------------------------------------------
National Oceanic and Atmospheric Administration
-----------------------------------------------------------------------
Takes of Marine Mammals Incidental to Specified Activities; Taking
Marine Mammals Incidental to Open Water Marine Seismic Survey in the
Beaufort and Chukchi Seas, Alaska; Notice
Federal Register / Vol. 75 , No. 156 / Friday, August 13, 2010 /
Notices
[[Page 49710]]
-----------------------------------------------------------------------
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XV09
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Open Water Marine Seismic Survey in
the Beaufort and Chukchi Seas, Alaska
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; issuance of an incidental take authorization.
-----------------------------------------------------------------------
SUMMARY: In accordance with the Marine Mammal Protection Act (MMPA)
regulations, notification is hereby given that NMFS has issued an
Incidental Harassment Authorization (IHA) to Shell Offshore Inc.
(Shell) to take, by harassment, small numbers of 8 species of marine
mammals incidental to a marine survey program, which includes site
clearance and shallow hazards, ice gouge, and strudel scour surveys, in
the Beaufort and Chukchi Seas, Alaska, during the 2010 Arctic open
water season.
DATES: Effective August 6, 2010, through November 30, 2010.
ADDRESSES: Inquiry for information on the incidental take authorization
should be addressed to Michael Payne, Chief, Permits, Conservation and
Education Division, Office of Protected Resources, National Marine
Fisheries Service, 1315 East-West Highway, Silver Spring, MD 20910. A
copy of the application containing a list of the references used in
this document, NMFS' Environmental Assessment (EA) and Finding of No
Significant Impact (FONSI), and the IHA may be obtained by writing to
the address specified above, telephoning the contact listed below (see
FOR FURTHER INFORMATION CONTACT), or visiting the Internet at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
Documents cited in this notice may be viewed, by appointment,
during regular business hours, at the aforementioned address.
FOR FURTHER INFORMATION CONTACT: Shane Guan, Office of Protected
Resources, NMFS, (301) 713-2289 or Brad Smith, NMFS, Alaska Region,
(907) 271-3023.
SUPPLEMENTARY INFORMATION:
Background
Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.)
direct the Secretary of Commerce to allow, upon request, the
incidental, but not intentional, taking of small numbers of marine
mammals by U.S. citizens who engage in a specified activity (other than
commercial fishing) within a specified geographical region if certain
findings are made and either regulations are issued or, if the taking
is limited to harassment, a notice of a proposed authorization is
provided to the public for review.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s), will not have an unmitigable adverse impact on the
availability of the species or stock(s) for subsistence uses (where
relevant), and if the permissible methods of taking and requirements
pertaining to the mitigation, monitoring and reporting of such takings
are set forth. NMFS has defined ``negligible impact'' in 50 CFR 216.103
as ``* * * an impact resulting from the specified activity that cannot
be reasonably expected to, and is not reasonably likely to, adversely
affect the species or stock through effects on annual rates of
recruitment or survival.''
Section 101(a)(5)(D) of the MMPA established an expedited process
by which citizens of the U.S. can apply for an authorization to
incidentally take small numbers of marine mammals by harassment. Except
with respect to certain activities not pertinent here, the MMPA defines
``harassment'' as:
any act of pursuit, torment, or annoyance which (i) has the
potential to injure a marine mammal or marine mammal stock in the
wild [``Level A harassment'']; or (ii) has the potential to disturb
a marine mammal or marine mammal stock in the wild by causing
disruption of behavioral patterns, including, but not limited to,
migration, breathing, nursing, breeding, feeding, or sheltering
[``Level B harassment''].
Section 101(a)(5)(D) establishes a 45-day time limit for NMFS
review of an application followed by a 30-day public notice and comment
period on any proposed authorizations for the incidental harassment of
marine mammals. Within 45 days of the close of the comment period, NMFS
must either issue or deny the authorization.
Summary of Request
NMFS received an application on December 24, 2009, from Shell for
the taking, by harassment, of marine mammals incidental to several
marine surveys designed to gather data relative to site clearance and
shallow hazards, ice gouge, and strudel scour in selected areas of the
Beaufort Sea and ice gouge in the Chukchi Sea, Alaska. These surveys
are continuations of those performed by Shell in the Beaufort Sea
beginning in 2006, and in the Chukchi Sea in 2008. After addressing
comments from NMFS, Shell modified its application and submitted a
revised application on April 19, 2010. The April 19, 2010, application
is the one available for public comment (see ADDRESSES) and considered
by NMFS for this proposed IHA.
Site clearance and shallow hazards surveys will evaluate the
seafloor, and shallow sub seafloor at prospective exploration drilling
locations, focusing on the depth to seafloor, topography, the potential
for shallow faults or gas zones, and the presence of archaeological
features. The types of equipment used to conduct these surveys use low
level energy sources focused on limited areas in order to characterize
the footprint of the seafloor and shallow sub seafloor at prospective
drilling locations. Ice gouge surveys will determine the depth and
distribution of ice gouges into the seabed. Ice gouge surveys use low-
level energy sources similar to the site clearance and shallow hazards.
Shell intends to conduct these marine surveys during the 2010
Arctic open-water season (July through October). Impacts to marine
mammals may occur from noise produced by various active acoustic
sources used in the surveys.
Description of the Specified Activity
Shell plans to complete the following surveys during the 2010 open-
water season:
Beaufort Sea Site Clearance and Shallow Hazards Surveys
Beaufort Sea Marine Surveys
[cir] Ice Gouge Survey
[cir] Strudel Scour Survey
Chukchi Sea Marine Surveys
[cir] Ice Gouge Survey
Each of these individual surveys will require marine vessels to
accomplish the work. Shell states that these marine surveys will be
conducted between July and October 2010, however, ice and weather
conditions will influence the exact dates and locations marine vessel
survey operations can be conducted.
1. Beaufort Sea Site Clearance and Shallow Hazards Surveys
Shell's proposed site clearance and shallow hazards surveys are to
gather data on: (1) Bathymetry, (2) seabed topography and other seabed
characteristics (e.g., boulder patches), (3) potential geohazards
(e.g., shallow faults and shallow gas zones), and (4) the presence of
any archeological features (e.g., shipwrecks). Site clearance and
shallow hazards surveys can be accomplished by one vessel with
[[Page 49711]]
acoustic sources. No other vessels are necessary to accomplish the
proposed work.
The focus of this activity will be on Shell's existing leases in
Harrison Bay in the central Beaufort Sea. Actual locations of site
clearance and shallow hazards surveys within Harrison Bay have not been
definitively set as of this date, although these will occur on the
Outer Continental Shelf (OCS) lease blocks in Harrison Bay located in
the Beaufort Sea shown on Figure 1 of Shell's IHA application. The site
clearance and shallow hazards surveys will be conducted within an area
of approximately 216 mi\2\ (558 km\2\) north of Thetis Island more than
3 mi (4.8 km) to approximately 20 mi (33 km) offshore. Approximately 63
mi (162.7 km) of the data acquisition is planned within this general
area. The survey track line is approximately 351.5 mi\2\ (565 km\2\).
The average depth of the survey area ranges from 35 to 85 ft (10.7 to
26 m).
Ice and weather permitting, Shell is proposing to conduct site
clearance and shallow hazards surveys within the timeframe of July 2010
through October 2010. The actual survey time is expected to take 30
days.
The vessel that will be conducting this activity has not been
determined at this point, but will be similar to the R/V Mt. Mitchell
which is the vessel that was used for surveys in the Chukchi Sea in
2009. The R/V Mt. Mitchell is a diesel powered-vessel, 70 m (231 ft)
long, 12.7 m (42 ft) wide, with a 4.5 m (15 ft) draft.
It is proposed that the following acoustic instrumentation, or
something similar, be used.
Deep Penetration Profiler, (40 cu-in airgun source with
48-channel streamer) and Medium Penetration Profiler, (40 cu-in airgun
source with 24-channel streamer):
The deep and medium penetration profilers are the major active
acoustic sources used in the site clearance and shallow hazards
surveys. The modeled source level is estimated at 217 dB re 1 [mu]Pa
rms. The 120, 160, 180, and 190 dB re 1 [mu]Pa rms received level
isopleths are estimated at 14,900 m, 1,220 m, 125 m, and 35 m from the
source, respectively.
Dual-frequency side scan sonar, (100-400 kHz or 300-600
kHz):
Based on Shell's 2006 90-day report, the source level of this
active acoustic source when operated at 190 and 240 kHz is
approximately 225 dB re 1 [mu]Pa rms. Due to its high frequency range,
NMFS does not consider its acoustic energy would be strong enough to
cause impacts to marine mammals beyond a couple of hundred meters from
the source.
Single beam Echo Sounder, (high: 100-340 kHz, low: 24-50
kHz):
This echo sounder is a typical ``fathometer'' or ``fish-finder''
that is widely used in most recreational or fishing vessels. Source
levels for these types of units are typically in the range of 180-200
dB re 1 [mu]Pa rms. Using a spherical spreading model, the 160 dB
isopleth is estimated at 100 m from the source for the lower range of
the acoustic signals. For the higher range of the signal, due to the
higher absorption coefficients, the 160 dB isopleth is expected to be
under 100 m from the source.
Multi-Beam Echo Sounder, (240 kHz):
Since the output frequency from this echo sounder is above the
upper-limit of marine mammal hearing range, NMFS believes it unlikely
that a marine mammal would be taken by this activity.
Shallow Sub-Bottom Profiler, (2-12 kHz):
Information regarding this active acoustic source on two vessels
(Alpha Helix and Henry C.) was provided in Shell's 2008 90-day open
water marine survey monitoring report. For the Alpha Helix measurement,
at 3.5 kHz, the source level for the shallow sub-bottom profiler was
193.8 dB re 1 [mu]Pa rms, and its 120, 160, 180, and 190 dB re 1 [mu]Pa
rms isopleths were determined to be 310 m, 14 m, 3 m, and 1 m from the
source, respectively. For the Henry C. measurement, at 3.5 kHz, the
source level of the similar profiler was measured at 167.2 dB re 1
[mu]Pa rms, and its 120 and 160 dB re 1 [mu]Pa rms isopleths were
determined to be 980 m and 3 m, respectively.
2. Beaufort Sea Marine Surveys
Two marine survey activities are proposed for the Beaufort Sea: (1)
Ice gouge survey, and (2) strudel scour survey. Shell continues to
conduct these types of marine surveys annually over a few years to
enhance baseline and statistical understanding of the formation,
longevity, and temporal distribution of sea floor features and baseline
environmental and biologic conditions. Marine surveys for ice gouge and
strudel scour surveys can be accomplished by one vessel for each. No
other vessels are necessary to accomplish the proposed work.
The proposed ice gouge surveys will be conducted in both State of
Alaska waters including Camden Bay, and the Federal waters of the OCS
in the Beaufort Sea near Pt. Thomson ranging from near shore to
approximately 37 mi (59.5 km) offshore. The water depth in the ice
gouging survey area ranges between 15 to 120 ft (4.5 to 36.6 m), and
the surveys will be conducted within an area of 1,950 mi\2\ (5,036
km\2\) with a survey track line of approximately 1,276 mi (2,050 km,
See Figure 2 of Shell's IHA application).
The proposed strudel scour survey will occur in State of Alaska
waters in Pt. Thomson ranging from near shore to 3 mi (4.8 km)
offshore. The water depth ranges from 3 to 20 ft (0.9 to 6.1 m). The
strudel scour survey will be conducted in an area of approximately 140
mi\2\ (361.5 km\2\). The survey track line is approximately 124 mi (200
km).
Ice and weather permitting, Shell is proposing to conduct this work
within the timeframe of July 2010 through October 2010. The actual
survey time is expected to take 45 days.
Ice Gouge Survey
As part of the feasibility study for Shell's Alaskan prospects a
survey is required to identify and evaluate seabed conditions. Ice
gouging is created by ice keels, which project from the bottom of
moving ice and gouge into seafloor sediment. Ice gouge features are
mapped, and by surveying each year, new gouges can be identified. The
ice gouge information is used to aid in predicting the prospect of,
orientation, depth, and frequency of future ice gouges. Ice gouge
information is required for the design of potential pipelines and for
the design of pipeline trenching and installation equipment.
The 2010 ice gouge surveys will be conducted using the conventional
survey method where the acoustic instrumentation will be towed behind
the survey vessel, or possibly with the use of an Autonomous Underwater
Vehicle (AUV). The same acoustic instrumentation will be used during
both AUV and the conventional survey methods. The AUV is a self-
propelled autonomous vehicle that will be equipped with acoustic
instrumentation and programmed for remote operation over the seafloor
where the ice gouge survey is to be conducted, and the vehicle is
launched and retrieved from a marine vessel.
For the survey operations, the AUV will be launched from the stern
of a vessel and will survey the seafloor close to the vessel. The
vessel will transit an area, with the AUV surveying the area behind the
vessel. The AUV also has a Collision Avoidance System and operates
without a towline that reduces potential impact to marine mammals (such
as entanglement). Using bathymetric sonar or multibeam echo sounder the
AUV can record the gouges on the seafloor surface caused by ice keels.
The sub-bottom profiler can
[[Page 49712]]
record layers beneath the surface to about 20 feet (6 m). The AUV is
more maneuverable and able to complete surveys more quickly than a
conventional survey. This reduces the duration that vessels producing
sound must operate. The proposed ice gouge survey in the Beaufort Sea
is expected to last for 45 days.
The vessel that will be used for ice gouging surveys has not been
selected, but it is anticipated that the vessel would be similar to the
R/V Mt. Mitchell, which is 70 m (231 ft) long, 12.7 m (42 ft) wide, and
4.5 m (15 ft) draft.
It is proposed that the following acoustic instrumentation, or
something similar, be used.
Dual Frequency sub-bottom profiler; (2 to 7 kHz or 8 to 23
kHz):
Information regarding this active acoustic source on Henry C. was
provided in Shell's 2006 and 2007 90-day open water marine survey
monitoring reports. In the 2006 report, at 2-7 and 8-23 kHz, the source
level was estimated at 184.6 dB re 1 [mu]Pa rms, and its 120, 160, and
180 dB re 1 [mu]Pa rms isopleths were determined to be 456 m, 7 m, and
2 m from the source, respectively. In the 2007 report, at 2-7 kHz, the
source level was estimated at 161.1 dB re 1 [mu]Pa rms, and its 120 and
160 dB re 1 [mu]Pa rms isopleths were determined to be 260 m and 1 m,
respectively.
Multibeam Echo Sounder (240 kHz) and Side-scan sonar
system (190 to 210 kHz):
Since the output frequencies from these acoustic instruments are
above the upper-limits of marine mammal hearing range, NMFS believes it
unlikely that a marine mammal would be taken by this activity.
Strudel Scour Survey
During the early melt on the North Slope, the rivers begin to flow
and discharge water over the coastal sea ice near the river deltas.
That water flows down holes in the ice (``strudels'') and scours the
seafloor. These areas are called ``strudel scours''. Information on
these features is required for prospective pipeline planning. Two
proposed activities are required to gather this information: aerial
survey via helicopter overflights during the melt to locate the
strudels; and strudel scour marine surveys to gather bathymetric data.
The overflights investigate possible sources of overflood water and
will survey local streams that discharge in the vicinity of Point
Thomson including the Staines River, which discharges to the east into
Flaxman Lagoon, and the Canning River, which discharges to the east
directly into the Beaufort Sea. These helicopter overflights will occur
during late May/early June 2010 and, weather permitting, should take no
more than two days. There are no planned landings during these
overflights other than at the Deadhorse or Kaktovik airports.
Areas that have strudel scour identified during the aerial survey
will be verified and surveyed with a marine vessel after the breakup of
nearshore ice. The vessel has not been determined, however, it is
anticipated that it will be the diesel-powered R/V Annika Marie which
has been utilized 2006 through 2008 and measures 13.1 m (43 ft) long,
or similar vessel.
This proposed activity is not anticipated to take more than 5 days
to conduct. The operation is conducted in the shallow water areas near
the coast in the vicinity of Point Thomson. This vessel will use the
following equipment:
Multibeam Echo Sounder (240 kHz) and Side-scan sonar
system (190 to 210 kHz):
Since the output frequencies from these acoustic instruments are
above the upper-limits of marine mammal hearing range, NMFS believes it
unlikely that a marine mammal would be taken by this activity.
Single Beam Bathymetric Sonar:
Source levels for these types of units are typically in the 180-230
dB range, somewhat lower than multibeam or side scan sonars. A unit
used during a previous survey had a source level (at high power) of 215
dB re 1 [mu]Pa (0-peak) and a standard operating frequency of 200 kHz.
Since the output frequencies from these acoustic instruments are above
the upper-limits of marine mammal hearing range, NMFS believes it
unlikely that a marine mammal would be taken by this activity.
3. Chukchi Sea Marine Survey--Ice Gouge Survey
Shell proposes one marine survey activity for the Chukchi Sea in
2010. Shell intends to conduct ice gouge surveys annually over a few
years to enhance baseline and statistical understanding of the
formation, longevity, and temporal distribution of sea floor features
and baseline environmental and biologic conditions. The ice gouge
survey can be accomplished by one vessel. No other vessels are
necessary to accomplish the proposed work.
The proposed ice gouge surveys will be conducted in both State of
Alaska waters and the Federal waters of the OCS in the Chukchi Sea.
Actual locations of the ice gouge surveys have not been definitively
set as of this date, although these will occur within the area outlined
in Figure 4 of the IHA application. The water depth of the ice gouging
survey ranges between 20 to 120 ft (6.1 to 36.6 m), and the surveys
will take in an area of 21,954 mi\2\ (56,965 km\2\), with a survey
track line of approximately 1,539 mi (2,473 km). This activity is
proposed to be conducted within the timeframe of July through October
2010. The total program will last a maximum of 60 days, excluding
downtime due to ice, weather and other unforeseen delays, and should be
complete by the end of October 2010.
The equipment and method used to conduct the ice gouge survey in
the Chukchi Sea will be the same as that used in the Beaufort Sea.
Because of the low source levels of the sub-bottom profiler and the
high-frequency nature of the multi-beam echo sounder used in the
proposed ice gouge survey, NMFS believes it unlikely that a marine
mammal would be taken by this activity.
Comments and Responses
A notice of NMFS' proposal to issue an IHA to Shell published in
the Federal Register on May 18, 2010 (75 FR 27708). That notice
described, in detail, Shell's proposed activity, the marine mammal
species that may be affected by the activity, and the anticipated
effects on marine mammals. During the 30-day public comment period,
NMFS received five comment letters from the following: the Marine
Mammal Commission (Commission); the Alaska Eskimo Whaling Commission
(AEWC); the Inupiat Community of the Arctic Slope (ICAS); the North
Slope Borough Office of the Mayor (NSB); and Alaska Wilderness League
(AWL), Audubon Alaska, Center for Biological Diversity, Defenders of
Wildlife, Earthjustice, Greenpeace, Natural Resources Defense Council,
Northern Alaska Environmental Center, Ocean Conservancy, Oceana,
Pacific Environment, Sierra Club, and World Wildlife Fund (collectively
``AWL''), along with an attached letter from Dr. David E. Bain, a
contract scientist for NMFS.
The AEWC submitted several journal articles as attachments to its
comment letters. NMFS acknowledges receipt of these documents but does
not intend to address the specific articles themselves in the responses
to comments, since these journal articles are merely used as citations
in AEWC's comments. AEWC also submitted an unsigned, final version of
the 2010 Conflict Avoidance Agreement (CAA), since Shell declined to
sign the CAA. Dr. Bain also attached
[[Page 49713]]
an in-review journal article he coauthored. Any comments specific to
Shell's application that address the statutory and regulatory
requirements or findings NMFS must make to issue an IHA are addressed
in this section of the Federal Register notice.
General Comments
Comment 1: AEWC and ICAS believe that NMFS should not issue
incidental take authorizations for oil and gas-related activities given
the current suspension of offshore drilling in Alaska and pending
reorganization of the Minerals Management Service (MMS). AEWC and ICAS
point out that the harm caused by an oil spill is not the only risk to
marine mammals posed by oil and gas activities on the OCS and that
there are concerns regarding underwater noise from geophysical
activities and the threats posed to marine mammals from noise and
chemical pollution, as well as increased vessel traffic. AEWC further
claims that many times, NMFS issued IHAs over the objections of the
scientific and subsistence communities as well as the agencies' own
scientists.
Response: The legal requirements and underlying analysis for the
issuance of an IHA concerning take associated with seismic activities
are unrelated to the moratorium on offshore drilling and reorganization
of the MMS. In order to issue an authorization pursuant to Section
101(a)(5)(D) of the MMPA, NMFS must determine that the taking by
harassment of small numbers of marine mammal species or stocks will
have a negligible impact on affected species or stocks, and will not
have an unmitigable adverse impact on the availability of affected
species or stocks for taking for subsistence uses. If NMFS is able to
make these findings, the Secretary is required to issue an IHA. In the
case of Shell's activities for 2010 (as described in the application,
the notice of proposed IHA (75 FR 27708; May 18, 2010) and this
document), NMFS determined that it was able to make the required MMPA
findings. Additionally, as described later in this section and
throughout this document, NMFS has determined that Shell's activities
will not result in injury or mortality of marine mammals, and no injury
or mortality is authorized under the IHA.
As discussed in detail in the proposed IHA (75 FR 27708; May 18,
2010), the EA for the issuance of IHAs to Shell and Statoil for the
proposed open water marine and seismic surveys, and this document, NMFS
has conducted a thorough analysis of the potential impacts of
underwater anthropogenic sound (especially sound from geophysical
surveys) on marine mammals. We have cited multiple studies and research
that support NMFS' MMPA and National Environmental Policy Act (NEPA)
determinations that the localized and short-term disturbance from
seismic surveys, with strict mitigation and monitoring measures
implemented, is likely to result in negligible impacts to marine
mammals and no significant impact to the human environment,
respectively. Although issuance of the IHA may be of concern to certain
members of the public, the proposed issuance of the IHA was carefully
reviewed and analyzed by NMFS scientists both at headquarters, through
an Endangered Species Act (ESA) section 7 consultation at NMFS Alaska
Regional Office, and by an independent bioacoustics expert and NMFS'
National Marine Mammal Laboratory. Based on those reviews, NMFS staff
in the Office of Protected Resources made appropriate changes to this
document.
Comment 2: ICAS points out that Native communities in Alaska have
long been ignored in the race to find and develop offshore oil and gas
resources and that the U.S. Government has consistently failed to
comply with legal requirements that require consultation with local
Native communities as proposals are being developed that affect native
environments. Instead, both Federal agencies and the entities they
permit make only token gestures at consultations with Native groups
offering them only the opportunity for involvement after proposals are
developed and after local knowledge would serve a useful purpose.
Response: Regulations at 50 CFR 216.104(a)(12) require applicants
for IHAs in Arctic waters to submit a Plan of Cooperation (POC), which,
among other things, requires the applicant to meet with affected
subsistence communities to discuss the proposed activities.
Additionally, for many years, NMFS has conducted the Arctic Open Water
Meeting, which brings together the Federal agencies, the oil and gas
industry, and affected Alaska Native organizations to discuss the
proposed activities and monitoring plans. Local knowledge is considered
at these times, and it is not too late for that knowledge to serve a
useful purpose. These communities are also afforded the opportunity to
submit comments on the application and proposed IHA notice, which are
then considered by NMFS before making a final determination on whether
or not to issue an IHA.
Comment 3: Executive Order 13175 requires Federal agencies to
conduct government-to-government consultation when undertaking to
formulate and implement policies that have tribal implications. Despite
this explicit requirement, ICAS believes that NMFS has failed to
consult with governing bodies of Native people who will be and have
been affected by the decisions NMFS is making under the MMPA. NMFS must
meet with ICAS and local Native villages on a government-to-government
basis to discuss the proposed IHA, as well as appropriate mitigation
and monitoring requirements.
Response: NMFS recognizes the importance of the government-to-
government relationship and has taken steps to ensure that Alaska
Natives play an active role in the management of Arctic species. For
example, NOAA and the AEWC co-manage bowhead whales pursuant to a
cooperative agreement. This agreement has allowed the AEWC to play a
significant role in the management of a valuable resource by affording
Alaska Natives the opportunity to protect bowhead whales and the Eskimo
culture and to promote scientific investigation, among other purposes.
In addition, NMFS works closely with Alaska Natives when
considering whether to permit the take of marine mammals incidental to
oil and gas operations. NMFS has met repeatedly over the years with
Alaska Native representatives to discuss concerns related to NMFS' MMPA
program in the Arctic, and has also taken into account recommended
mitigation measures to reduce the impact of oil and gas operations on
bowhead whales and to ensure the availability of marine mammals for
taking for subsistence uses. Finally, NMFS has participated in Alaska
Native community meetings in the past and will continue to do so, when
feasible. NMFS most recently met with ICAS at its May monthly meeting
in Barrow to discuss NMFS' role in minimizing impacts to marine mammals
from oil and gas industry activities and asked the ICAS membership for
specific recommendations. NMFS will continue to ensure that it meets
its government-to-government responsibilities and will work closely
with Alaska Natives to address their concerns.
MMPA Concerns
Comment 4: AEWC notes their disappointment in NMFS for releasing
for public comment an incomplete application from Shell that fails to
provide the mandatory information required by the MMPA and NMFS'
implementing regulations. AEWC requests that NMFS return Shell's
application as incomplete, or else the agency risks making arbitrary
and
[[Page 49714]]
indefensible determinations under the MMPA. The following is the
information that AEWC believes to be missing from Shell's application:
(1) A description of the ``age, sex, and reproductive condition'' of
the marine mammals that will be impacted, particularly in regard to
bowhead whales (50 CFR 216.104(a)(6)); (2) the economic ``availability
and feasibility * * * of equipment, methods, and manner of conducting
such activity or other means of effecting the least practicable adverse
impact upon the affected species or stocks, their habitat, and on their
availability for subsistence uses, paying particular attention to
rookeries, mating grounds, and areas of similar significance'' (50 CFR
216.104(a)(11)); and (3) suggested means of learning of, encouraging,
and coordinating any research related activities (50 CFR
216.104(a)(14)). NSB also notes its concern about the lack of
specificity regarding the timing and location of the proposed surveys,
as well as the lack of specificity regarding the surveys themselves.
Response: NMFS does not agree that it released an incomplete
application for review during the public comment period. After NMFS'
initial review of the application, NMFS submitted questions and
comments to Shell on its application. After receipt and review of
Shell's responses, which were incorporated into the final version of
the IHA application that was released to the public for review and
comment, NMFS made its determination of completeness and released the
application, addenda, and the proposed IHA notice (75 FR 27708; May 18,
2010). Regarding the three specific pieces of information believed to
be missing by AEWC, Shell's original application included a description
of the pieces of information that are required pursuant to 50 CFR
216.104(a)(12).
Information required pursuant to 50 CFR 216.104(a)(6) requires that
an applicant submit information on the ``age, sex, and reproductive
condition (if possible)'' of the number of marine mammals that may be
taken. In the application, Shell described the species expected to be
taken by harassment and provided estimates of how many of each species
were expected to be taken during their activities. In most cases, it is
very difficult to estimate how many animals, especially cetaceans, of
each age, sex, and reproductive condition will be taken or impacted by
seismic or site clearance and shallow hazards surveys.
Shell also provided information on economic ``availability and
feasibility * * * of equipment, methods, and manner of conducting such
activity or other means of effecting the least practicable adverse
impact upon the affected species or stocks, their habitat, and on their
availability for subsistence uses, paying particular attention to
rookeries, mating grounds, and areas of similar significance'' (50 CFR
216.104(a)(11)) in its IHA application. In its application, Shell
states that four main mitigations regarding site clearance and shallow
hazards surveys in the Beaufort Sea are proposed: (1) Timing and
locations for active survey acquisition work; (2) to configure airguns
in a manner that directs energy primarily down to the seabed thus
decreasing the range of horizontal spreading of noise; (3) using a
energy source which is as small as possible while still accomplishing
the survey objectives; and (4) curtailing active survey work when the
marine mammal observers sight visually (from shipboard) the presence of
marine mammals within identified ensonified zones. Details of these
mitigation measures are discussed further in the 4MP that is included
in Shell's IHA application. In addition to these measures, NMFS' Notice
of Proposed IHA (75 FR 27708, May 18, 2010) described mitigation
measures proposed to be implemented by Shell (outlined in the
application), as well as additional measures proposed by NMFS for
inclusion in an IHA.
Lastly, information required pursuant to 50 CFR 216.104(a)(14) was
also included in Shell's application. Shell provided a list of
researchers who could potentially receive results of their research
activities who may find the data useful in their own research.
Additionally, Shell states that it plans to deploy arrays of acoustic
recorders in the Beaufort Sea in 2010, similar to those deployed in
2007 and 2008 using DASARs supplied by Greeneridge. These directional
acoustic systems permit localization of bowhead whale and other marine
mammal vocalizations, and to further understand, define, and document
sound characteristics and propagation resulting from shallow hazards
surveys that may have the potential to cause deflections of bowhead
whales from their migratory pathway. NMFS also determined that Shell's
application provides descriptions of the specified activities and
specified geographic region.
In conclusion, NMFS believes that Shell provided all of the
necessary information to proceed with publishing a proposed IHA notice
in the Federal Register.
Comment 5: AEWC and NSB state that NMFS failed to issue a draft
authorization for public review and comment. The plain language of both
the MMPA and NMFS' implementing regulations require that NMFS provide
the opportunity for public comment on the ``proposed incidental
harassment authorization'' (50 CFR 216.104(b)(1)(i); 16 U.S.C. 1371
(a)(5)(D)(iii)) and not just on the application itself as NMFS has done
here. Given Shell's refusal to sign the CAA and without a complete
draft authorization and accompanying findings, AEWC states that it
cannot provide meaningful comments on Shell's proposed activities, ways
to mitigate the impacts of those activities on marine mammals, and
measures that are necessary to protect subsistence uses and sensitive
resources.
Response: The May 18, 2010 proposed IHA notice (75 FR 27708)
contained all of the relevant information needed by the public to
provide comments on the proposed authorization itself. The notice
contained the permissible methods of taking by harassment, means of
effecting the least practicable impact on such species (i.e.,
mitigation), measures to ensure no unmitigable adverse impact on the
availability of the species or stock for taking for subsistence use,
requirements pertaining to the monitoring and reporting of such taking,
including requirements for the independent peer review of the proposed
monitoring plan. The notice provided detail on all of these points and,
in NMFS view, allowed the public to comment on the proposed
authorization and inform NMFS' final decision. Additionally, the notice
contained NMFS' preliminary findings of negligible impact and no
unmitigable adverse impact.
The signing of a CAA is not a requirement to obtain an IHA. The CAA
is a document that is negotiated between and signed by the industry
participant, AEWC, and the Village Whaling Captains' Associations. NMFS
has no role in the development or execution of this agreement. Although
the contents of a CAA may inform NMFS' no unmitigable adverse impact
determination for bowhead and beluga whales and ice seals, the signing
of it is not a requirement. While a CAA has not been signed and a final
version agreed to by industry participants, AEWC, and the Village
Whaling Captains' Associations, NMFS was provided with a copy of the
version ready for signature by AEWC. NMFS has reviewed the CAA and
included several measures from the document which relate to marine
mammals and avoiding conflicts with subsistence hunts in the IHA. Some
of
[[Page 49715]]
the conditions which have been added to the IHA include: (1) Avoiding
concentrations of whales and reducing vessel speed when near whales;
(2) flying at altitudes above 457 m (1,500 ft) unless involved in
marine mammal monitoring or during take-offs, landings, or in
emergencies situations; (3) conducting sound source verification
measurements; and (4) participating in the Communication Centers.
Despite the lack of a signed CAA for 2010 activities, NMFS is confident
that the measures contained in the IHA will ensure no unmitigable
adverse impact to subsistence users.
Comment 6: AEWC and NSB argue that Shell has not demonstrated that
its proposed activities would take only ``small numbers of marine
mammals of a species or population stock,'' resulting in no more than a
``negligible impact'' on a species or stock. In addition, NSB argues
that NMFS has not adequately analyzed harassment associated with
received levels of noise below 160 dB.
Response: NMFS believes that it provided sufficient information in
its proposed IHA notice (75 FR 27708; May 18, 2010) to make the small
numbers and negligible impact determinations and that the best
scientific information available was used to make those determinations.
While some published articles indicate that certain marine mammal
species may avoid seismic vessels at levels below 160 dB, NMFS does not
consider that these responses rise to the level of a take, as defined
in the MMPA. While studies, such as Miller et al. (1999), have
indicated that some bowhead whales may have started to deflect from
their migratory path 35 km (21.7 mi) from the seismic vessel, it should
be pointed out that these minor course changes are during migration
and, as described in MMS' 2006 Final Programmatic Environmental
Assessment (PEA), have not been seen at other times of the year and
during other activities. To show the contextual nature of this minor
behavioral modification, recent monitoring studies of Canadian seismic
operations indicate that feeding, non-migratory bowhead whales do not
move away from a noise source at an SPL of 160 dB. Therefore, while
bowheads may avoid an area of 20 km (12.4 mi) around a noise source,
when that determination requires a post-survey computer analysis to
find that bowheads have made a 1 or 2 degree course change, NMFS
believes that does not rise to a level of a ``take,'' as the change in
bearing is due to animals sensing the noise and avoiding passage
through the ensonified area during their migration, and should not be
considered as being displaced from their habitat. NMFS therefore
continues to estimate ``takings'' under the MMPA from impulse noises,
such as seismic, as being at a distance of 160 dB (re 1 [mu]Pa). As
explained throughout this Federal Register notice, it is highly
unlikely that marine mammals would be exposed to SPLs that could result
in serious injury or mortality. The best scientific information
indicates that an auditory injury is unlikely to occur, as apparently
sounds need to be significantly greater than 180 dB for injury to occur
(Southall et al., 2007). The 180-dB radius for the airgun array to be
used by Shell is 125 m (410 ft). Therefore, if injury were possible
from Shell's activities, the animal would need to be closer than 125 m
(410 ft). However, based on the configuration of the airgun array and
streamers, it is highly unlikely that a marine mammal would be that
close to the seismic vessel. Mitigation measures described later in
this document will be implemented should a marine mammal enter this
small zone around the airgun array.
Regarding the ``small numbers'' issue raised by the AEWC and NSB,
NMFS has provided estimates on the number of marine mammals that could
be taken as a result of Shell's proposed marine surveys, and the
estimated takes from these proposed activities are all under 3 percent
for affected marine mammal populations (see Potential Number of Takes
by Harassment section below).
Impacts to Marine Mammals
Comment 7: AEWC notes that based on the density estimates, Shell is
predicting that an average of 381 and a maximum of 394 Bering-Chukchi-
Beaufort (B-C-B) stock of bowhead whales may be exposed to seismic
sounds at received levels above 160 dB. AEWC states that these are by
no means ``small numbers'' of marine mammals that will be subjected to
impacts as a result of Shell's operations.
Response: NMFS determined that the small numbers requirement has
been satisfied. Shell has predicted that an average of 381 individuals
of the B-C-B stock of bowhead whales would be exposed to noise received
levels above 160 dB as the result of Shell's proposed marine surveys,
and NMFS assumes that animals exposed to received levels above 160 dB
are taken. However, because of the tendency of whales to avoid the
source to some degree, and the fact that both the whales and the source
are both moving through an area, the majority of the exposures would
likely occur at levels closer to 160 dB (not higher levels) and the
impacts would be expected to be relatively low-level and not of a long
duration. NMFS addresses ``small numbers'' in terms relative to the
stock or population size. The Level B harassment take estimate of 381
bowhead whales is a small number in relative terms, because of the
nature of the anticipated responses and in that it represents only 2.67
percent of the regional stock size of that species (14,247), if each
``exposure'' at 160 dB represents an individual bowhead whale.
Additionally, the percentage would be even lower if animals move out of
the seismic area in a manner that does not result in a take at all.
Comment 8: AWL, NSB, and AEWC noted that NMFS has acknowledged that
permanent threshold shift (PTS) qualifies as a serious injury.
Therefore, if an acoustic source at its maximum level has the potential
to cause PTS and thus lead to serious injury, it would not be
appropriate to issue an IHA for the activity (60 FR 28381, May 31,
1995). AEWC states that therefore an LOA is required here. While the
airguns proposed by Shell are smaller than those associated with
typical 2D/3D deep marine surveys, the noise they produce is still
considerable, as evidenced by the estimated 120 dB radius that extends
out to 14,000 m.
Response: In the proposed rule to implement the process to apply
for and obtain an IHA, NMFS stated that authorizations for harassment
involving the ``potential to injure'' would be limited to only those
that may involve non-serious injury (60 FR 28379; May 31, 1995). While
the Federal Register notice cited by the commenters states that NMFS
considered PTS to be a serious injury (60 FR 28379; May 31, 1995), our
understanding of anthropogenic sound and the way it impacts marine
mammals has evolved since then, and NMFS no longer considers PTS to be
a serious injury. NMFS has defined ``serious injury'' in 50 CFR 216.3
as ``* * * any injury that will likely result in mortality.'' There are
no data that suggest that PTS would be likely to result in mortality,
especially the limited degree of PTS that could hypothetically be
incurred through exposure of marine mammals to seismic airguns at the
level and for the duration that are likely to occur in this action.
Further, as stated several times in this document and previous
Federal Register notices for seismic activities, there is no empirical
evidence that exposure to pulses of airgun sound can cause PTS in any
marine mammal, even with large arrays of airguns (see Southall et al.
2007). PTS is thought to occur several decibels above that inducing
mild temporary threshold shift (TTS), the mildest form of hearing
impairment (a non-injurious effect).
[[Page 49716]]
NMFS concluded that cetaceans and pinnipeds should not be exposed to
pulsed underwater noise at received levels exceeding, respectively, 180
and 190 dB re 1 [mu]Pa (rms). The established 180- and 190-dB re 1
[mu]Pa (rms) criteria are the received levels above which, in the view
of a panel of bioacoustics specialists convened by NMFS before TTS
measurements for marine mammals started to become available, one could
not be certain that there would be no injurious effects, auditory or
otherwise, to marine mammals. As summarized later in this document,
data that are now available imply that TTS is unlikely to occur unless
bow-riding odontocetes are exposed to airgun pulses much stronger than
180 dB re 1 Pa rms (Southall et al. 2007). Additionally, NMFS has
required monitoring and mitigation measures to negate the possibility
of marine mammals being seriously injured as a result of Shell's
activities. In the proposed IHA, NMFS determined that Shell's
activities are unlikely to even result in TTS. Based on this
determination and the explanation provided here, PTS is also not
expected. Therefore, an IHA is appropriate.
Comment 9: AWL, Dr. Bain, NSB, and AEWC state that NMFS has not
adequately considered whether marine mammals may be harassed at
received levels significantly lower than 160 dB and that NMFS did not
use the best scientific evidence in setting the sound levels against
which take was assessed. They state that NMFS calculated harassment
from Shell's proposed surveying based on the exposure to marine mammals
to sounds at or above 160 dB and that this uniform approach to
harassment does not take into account known reactions of marine mammals
in the Arctic to levels of noise far below 160 dB. These comments state
that bowhead, gray, killer, and beluga whales and harbor porpoise react
to sounds lower than 160 dB.
Citing several papers on killer whales and harbor porpoise, Dr.
Bain states that major behavioral changes of these animals appear to be
associated with received levels of around 135 dB re 1 [mu]Pa, and that
minor behavioral changes can occur at received levels from 90-110 dB re
1 [mu]Pa or lower. He also states that belugas have been observed to
respond to icebreakers by swimming rapidly away at distances up to 80
km, where received levels were between 94 and 105 dB re 1 [mu]Pa.
Belugas exhibited minor behavioral changes such as changes in
vocalization, dive patterns, and group composition at distances up to
50 km (NRC 2003), where received levels were likely around 120 dB.
AEWC also states that in conducting scoping on its national
acoustic guidelines for marine mammals, NMFS noted that the existing
system for determining take (i.e., the 160 dB mark) ``considers only
the sound pressure level of an exposure but not its other attributes,
such as duration, frequency, or repetition rate, all of which are
critical for assessing impacts on marine Mammals'' and ``also assumes a
consistent relationship between rms (root-mean-square) and peak
pressure values for impulse sounds, which is known to be inaccurate
under certain (many) conditions'' (70 FR 1871, 1873; January 11, 2005).
Thus, NMFS itself has recognized that 160 dB (rms) is not an adequate
measure. AEWC argues that current scientific research establishes that
120 dB (rms) is a more appropriate measure for impacts to marine
mammals.
Response: The best information available to date for reactions by
bowhead whales to noise, such as seismic, is based on the results from
the 1998 aerial survey (as supplemented by data from earlier years) as
reported in Miller et al. (1999). In 1998, bowhead whales below the
water surface at a distance of 20 km (12.4 mi) from an airgun array
received pulses of about 117-135 dB re 1 [mu]Pa rms, depending upon
propagation. Corresponding levels at 30 km (18.6 mi) were about 107-126
dB re 1 [mu]Pa rms. Miller et al. (1999) surmise that deflection may
have begun about 35 km (21.7 mi) to the east of the seismic operations,
but did not provide SPL measurements to that distance and noted that
sound propagation has not been studied as extensively eastward in the
alongshore direction, as it has northward, in the offshore direction.
Therefore, while this single year of data analysis indicates that
bowhead whales may make minor deflections in swimming direction at a
distance of 30-35 km (18.6-21.7 mi), there is no indication that the
SPL where deflection first begins is at 120 dB; it could be at another
SPL lower or higher than 120 dB. Miller et al. (1999) also note that
the received levels at 20-30 km (12.4-18.6 mi) were considerably lower
in 1998 than have previously been shown to elicit avoidance in bowheads
exposed to seismic pulses. However, the seismic airgun array used in
1998 was larger than the ones used in 1996 and 1997. Therefore, NMFS
believes that it cannot scientifically support adopting any single SPL
value below 160 dB and apply it across the board for all species and in
all circumstances. Second, these minor course changes occurred during
migration and, as indicated in MMS' 2006 PEA, have not been seen at
other times of the year and during other activities. Third, as stated
in the past, NMFS does not believe that minor course corrections during
a migration equate to ``take'' under the MMPA. This conclusion is based
on controlled exposure experiments conducted on migrating gray whales
exposed to the U.S. Navy's low frequency sonar (LFA) sources (Tyack
2009). When the source was placed in the middle of the migratory
corridor, the whales were observed deflecting around the source during
their migration. However, such minor deflection is considered not to be
biologically significant. To show the contextual nature of this minor
behavioral modification, recent monitoring studies of Canadian seismic
operations indicate that when, not migrating, but involved in feeding,
bowhead whales do not move away from a noise source at an SPL of 160
dB. Therefore, while bowheads may avoid an area of 20 km (12.4 mi)
around a noise source, when that determination requires a post-survey
computer analysis to find that bowheads have made a 1 or 2 degree
course change, NMFS believes that does not rise to a level of a
``take.'' NMFS therefore continues to estimate ``takings'' under the
MMPA from impulse noises, such as seismic, as being at a distance of
160 dB (re 1 [mu]Pa). Although it is possible that marine mammals could
react to any sound levels detectable above the ambient noise level
within the animals' respective frequency response range, this does not
mean that such animals would react in a biologically significant way.
According to experts on marine mammal behavior, the degree of reaction
which constitutes a ``take,'' i.e., a reaction deemed to be
biologically significant that could potentially disrupt the migration,
breathing, nursing, breeding, feeding, or sheltering, etc., of a marine
mammal is complex and context specific, and it depends on several
variables in addition to the received level of the sound by the
animals. These additional variables include, but are not limited to,
other source characteristics (such as frequency range, duty cycle,
continuous vs. impulse vs. intermittent sounds, duration, moving vs.
stationary sources, etc.); specific species, populations, and/or
stocks; prior experience of the animals (naive vs. previously exposed);
habituation or sensitization of the sound by the animals; and behavior
context (whether the animal perceives the sound as predatory or simply
annoyance), etc. (Southall et al. 2007).
[[Page 49717]]
The references cited in the comment letters address different
source characteristics (continuous sound rather than impulse sound that
are planned for the proposed shallow hazard and site clearance surveys)
or species (killer whales and harbor proposes) that rarely occur in the
proposed Arctic action area. Some information about the responses of
bowhead and gray whales to seismic survey noises has been acquired
through dedicated research and marine mammal monitoring studies
conducted during prior seismic surveys. Detailed descriptions regarding
behavioral responses of these marine mammals to seismic sounds are
available (e.g., Richardson et al. 1995; review by Southall et al.
2007), and are also discussed in this document. Additionally, as Shell
does not intend to use ice-breakers during its operations, statements
regarding beluga reactions to icebreaker noise are not relevant to this
activity.
Regarding the last point raised in this comment by AEWC, NMFS
recognizes the concern. However, NMFS does not agree with AEWC's
statement that current scientific research establishes that 120 dB
(rms) is a more appropriate measure for impacts to marine mammals for
reasons noted above. Based on the information and data summarized in
Southall et al. (2007), and on information from various studies, NMFS
believes that the onset for behavioral harassment is largely context
dependent, and there are many studies showing marine mammals do not
show behavioral responses when exposed to multiple pulses at received
levels above 160 dB re 1 [mu]Pa (e.g., Malme et al. 1983; Malme et al.
1984; Richardson et al. 1986; Akamatsu et al. 1993; Madsen and
M[oslash]hl 2000; Harris et al. 2001; Miller et al. 2005). Therefore,
although using a uniform SPL of 160-dB for the onset of behavioral
harassment for impulse noises may not capture all of the nuances of
different marine mammal reactions to sound, it is an appropriately
conservative way to manage and regulate anthropogenic noise impacts on
marine mammals. Therefore, unless and until an improved approach is
developed and peer-reviewed, NMFS will continue to use the 160-dB
threshold for determining the level of take of marine mammals by Level
B harassment for impulse noise (such as from airguns).
Comment 10: NSB and AWL note that this IHA, as currently proposed,
is based on uncertainties that are not allowed under the MMPA. Citing
comments made by NMFS on recent MMS Lease Sale Environmental Impact
Statements, NSB notes that NMFS stated that without more current and
thorough data on the marine mammals in the Chukchi Sea and their use of
these waters, it would be difficult to make the findings required by
the MMPA. NSB notes that NMFS noted that the ``continued lack of basic
audiometric data for key marine mammal species'' that occur throughout
the Chukchi Sea inhibits the ``ability to determine the nature and
biological significance of exposure to various levels of both
continuous and impulsive oil and gas activity sounds.''
Response: NMFS agrees that while there may be some uncertainty on
the current status of some marine mammal species in the Chukchi Sea and
on impacts to marine mammals from seismic surveys, the best available
information supports our findings. NMFS is currently proposing to
conduct new population assessments for Arctic pinniped species, and
current information is available on-line through the Stock Assessment
Reports (SARs). Moreover, NMFS has required the industry to implement a
monitoring and reporting program to collect additional information
concerning effects to marine mammals.
In regard to impacts, there is no indication that seismic survey
activities are having a long-term impact on marine mammals. For
example, apparently, bowhead whales continued to increase in abundance
during periods of intense seismic activity in the Chukchi Sea in the
1980s (Raftery et al. 1995; Angliss and Outlaw 2007), even without
implementation of current mitigation requirements. As a result, NMFS
believes that seismic survey noise in the Arctic will affect only small
numbers of and have no more than a negligible impact on marine mammals
in the Chukchi Sea. As explained in this document and based on the best
available information, NMFS has determined that Shell's activities will
affect only small numbers of marine mammals, will have a negligible
impact on affected species or stocks, and will not have an unmitigable
adverse impact on subsistence uses of the affected species or stocks.
Comment 11: AEWC notes that stranded marine mammals or their
carcasses are also a sign of injury. NMFS states in its notice that it
``does not expect any marine mammal will * * * strand as a result of
the proposed survey'' (75 FR 27708; May 18, 2010). In reaching this
conclusion, NMFS claims that strandings have not been recorded for the
Beaufort and Chukchi Seas. AEWC states that the Department of Wildlife
Management of NSB has completed a study documenting 25 years worth of
stranding data and showing that five dead whales were reported in 2008
alone in comparison with the five dead whales that were reported in the
same area over the course of 25 years (Rosa 2009).
In light of the increase in seismic operations in the Arctic since
2006, AEWC says that NSB's study raises serious concerns about the
impacts of these operations and their potential to injure marine
mammals. AEWC states that while they think this study taken together
with the June 2008 stranding of ``melon headed whales off Madagascar
that appears to be associated with seismic surveys'' (75 FR 27708; May
18, 2010) demonstrate that seismic operations have the potential to
injure marine mammals beyond beaked whales (and that Shell needs to
apply for an LOA for its operations), certainly NSB's study shows that
direct injury of whales is on-going. AEWC states that these direct
impacts must be analyzed and explanations sought out before additional
activities with the potential to injure marine mammals are authorized,
and that NMFS must explain how, in light of this new information,
Shell's application does not have the potential to injure marine
mammals.
Response: NMFS has reviewed the information provided by AEWC
regarding marine mammal strandings in the Arctic. The Rosa (2009) paper
cited by AEWC does not provide any evidence linking the cause of death
for the bowhead carcasses reported in 2008 to seismic operations.
Additionally, the increased reporting of carcasses in the Arctic since
2006 may also be a result of increased reporting effort and does not
necessarily indicate that there were fewer strandings prior to 2008.
Marine mammal observers (MMOs) aboard industry vessels in the Beaufort
and Chukchi Seas have been required to report sightings of injured and
dead marine mammals to NMFS as part of the IHA requirements only since
2006.
Regarding the June 2008 stranding of melon headed whales off
Madagascar, information available to NMFS at this time indicates that
the seismic airguns were not active around the time of the stranding.
While the Rosa (2009) study does present information regarding the
injury of whales in the Arctic, it does not link the cause of the
injury to seismic survey operations. As NMFS has stated previously, the
evidence linking marine mammal strandings and seismic surveys remains
tenuous at best. Two papers, Taylor et al. (2004) and Engel et al.
(2004) reference seismic signals as a possible cause for a marine
mammal stranding.
[[Page 49718]]
Taylor et al. (2004) noted two beaked whale stranding incidents
related to seismic surveys. The statement in Taylor et al. (2004) was
that the seismic vessel was firing its airguns at 1300 hrs on September
24, 2004, and that between 1400 and 1600 hrs, local fishermen found
live stranded beaked whales 22 km (12 nm) from the ship's location. A
review of the vessel's trackline indicated that the closest approach of
the seismic vessel and the beaked whales stranding location was 18 nm
(33 km) at 1430 hrs. At 1300 hrs, the seismic vessel was located 25 nm
(46 km) from the stranding location. What is unknown is the location of
the beaked whales prior to the stranding in relation to the seismic
vessel, but the close timing of events indicates that the distance was
not less than 18 nm (33 km). No physical evidence for a link between
the seismic survey and the stranding was obtained. In addition, Taylor
et al. (2004) indicates that the same seismic vessel was operating 500
km (270 nm) from the site of the Galapagos Island stranding in 2000.
Whether the 2004 seismic survey caused the beaked whales to strand is a
matter of considerable debate (see Cox et al. 2006). However, these
incidents do point to the need to look for such effects during future
seismic surveys. To date, follow up observations on several scientific
seismic survey cruises have not indicated any beaked whale stranding
incidents.
Engel et al. (2004), in a paper presented to the IWC in 2004 (SC/
56/E28), mentioned a possible link between oil and gas seismic
activities and the stranding of 8 humpback whales (7 off the Bahia or
Espirito Santo States and 1 off Rio de Janeiro, Brazil). Concerns about
the relationship between this stranding event and seismic activity were
raised by the International Association of Geophysical Contractors
(IAGC). The IAGC (2004) argues that not enough evidence is presented in
Engel et al. (2004) to assess whether or not the relatively high
proportion of adult strandings in 2002 is anomalous. The IAGC contends
that the data do not establish a clear record of what might be a
``natural'' adult stranding rate, nor is any attempt made to
characterize other natural factors that may influence strandings. As
stated previously, NMFS remains concerned that the Engel et al. (2004)
article appears to compare stranding rates made by opportunistic
sightings in the past with organized aerial surveys beginning in 2001.
If so, then the data are suspect.
Finally, if bowhead and gray whales react to sounds at very low
levels by making minor course corrections to avoid seismic noise, and
mitigation measures require Shell to ramp-up the seismic array to avoid
a startle effect, strandings such as those observed in the Bahamas in
2000 are highly unlikely to occur in the Arctic Ocean as a result of
seismic activity. Therefore, NMFS does not expect any marine mammals
will incur serious injury or mortality as a result of Shell's 2010
survey operations, so an LOA is not needed.
Lastly, Shell is required to report all sightings of dead and
injured marine mammals to NMFS and to notify the Marine Mammal Health
and Stranding Response Network. However, Shell is not permitted to
conduct necropsies on dead marine mammals. Necropsies can only be
performed by people authorized to do so under the Marine Mammal Health
and Stranding Response Program MMPA permit. NMFS is currently
considering different methods for marking carcasses to reduce the
problem of double counting. However, a protocol has not yet been
developed, so marking is not required in the IHA.
Comment 12: AEWC and NSB state that research is increasingly
showing that marine mammals may remain within dangerous distances of
seismic operations rather than leave a valued resource such as a
feeding ground (see Richardson 2004). The International Whaling
Commission (IWC) scientific committee has indicated that the lack of
deflection by feeding whales in Camden Bay (during Shell seismic
activities) likely shows that whales will tolerate and expose
themselves to potentially harmful levels of sound when needing to
perform a biologically vital activity, such as feeding (mating, giving
birth, etc.). Thus, the noise from Shell's proposed operations could
injure marine mammals if they are close enough to the source. NSB
further states that NMFS has not adequately analyzed the potential for
serious injury.
Response: If marine mammals, such as bowhead whales, remain near a
seismic operation to perform a biologically vital activity, such as
feeding, depending on the distance from the vessel and the size of the
160-dB radius, the animals may experience some Level B harassment. A
detailed analysis on potential impacts of anthropogenic noise
(including noise from seismic airguns and other active acoustic sources
used in geophysical surveys) is provided in the proposed IHA (75 FR
27708; May 18, 2010) and in this document. Based on the analysis, NMFS
believes that it is unlikely any animals exposed to noise from Shell's
proposed marine surveys would be exposed to received levels that could
cause TTS (a non-injurious Level B harassment). Therefore, it is even
less likely that marine mammals would be exposed to levels of sound
from Shell's activity that could cause PTS (a non-lethal Level A
harassment).
In addition, depending on the distance of the animals from the
vessel and the number of individual whales present, certain mitigation
measures are required to be implemented. If an aggregation of 12 or
more mysticete whales are detected within the 160-dB radius, then the
airguns must be shutdown until the aggregation is no longer within that
radius. Additionally, if any whales are sighted within the 180-dB
radius or any pinnipeds are sighted within the 190-dB radius of the
active airgun array, then either a power-down or shutdown must be
implemented immediately. For the reasons stated throughout this
document, NMFS has determined that Shell's operations will not injure,
seriously injure, or kill marine mammals.
Comment 13: AEWC states that NMFS does little to assess whether
Level A harassment is occurring as a result of the deflection of marine
mammals as a result of Shell's proposed operations. Deflected marine
mammals may suffer impacts due to masking of natural sounds including
calling to others of their species, physiological damage from stress
and other non-auditory effects, harm from pollution of their
environment, tolerance, and hearing impacts (see Nieukirk et al. 2004).
Not only do these operations disrupt the animals' behavioral patterns,
but they also create the potential for injury by causing marine mammals
to miss feeding opportunities, expend more energy, and stray from
migratory routes when they are deflected. Dr. Bain also states that
there are three main ways that minor behavioral changes, when
experienced by numerous individuals for extended periods of time, can
affect population growth: Increased energy expenditure, reduced food
acquisition, and stress (Trites and Bain 2000).
Response: See the response to comment 9 regarding the potential for
injury. The paper cited by AEWC (Nieukirk et al. 2004) tried to draw
linkages between recordings of fin, humpback, and minke whales and
airgun signals in the western North Atlantic; however, the authors note
the difficulty in assessing impacts based on the data collected. The
authors also state that the effects of airgun activity on baleen whales
is unknown and then cite to Richardson et al. (1995) for some possible
effects, which AEWC lists in their comment. There is no statement in
the cited study, however, about the
[[Page 49719]]
linkage between deflection and these impacts. While deflection may
cause animals to expend extra energy, there is no evidence that this
deflection is causing a significant behavioral change that will
adversely impact population growth. In fact, bowhead whales continued
to increase in abundance during periods of intense seismic activity in
the Chukchi Sea in the 1980s (Raftery et al. 1995; Angliss and Outlaw
2007). Therefore, NMFS does not believe that injury will occur as a
result of Shell's activities. Additionally, Shell's total data
acquisition activities would only ensonify 7.3 km\2\ to received levels
above 160 dB of the Beaufort Sea (0.0016% of the entire Beaufort Sea).
Therefore, based on the smaller radii associated with Shell's site
clearance and shallow hazards surveys than the larger 2D or 3D seismic
programs and the extremely small area of the Beaufort Sea where Shell
will utilize airguns, it is unlikely that marine mammals will need to
expend extra energy to locate prey or to have reduced foraging
opportunities.
Comment 14: Citing Erbe (2002), AEWC notes that any sound at some
level can cause physiological damage to the ear and other organs and
tissues. Placed in a context of an unknown baseline of sound levels in
the Chukchi Sea, it is critically important that NMFS take a
precautionary approach to permitting additional noise sources in this
poorly studied and understood habitat. Thus, the best available science
dictates that NMFS use a more cautious approach in addressing impacts
to marine mammals from seismic operations.
Response: The statement from Erbe (2002) does not take into account
mitigation measures required in the IHA to reduce impacts to marine
mammals. As stated throughout this document, based on the fact that
Shell will be using a small airgun array (total discharge volume of 40
in\3\) and will implement mitigation measures (i.e., ramp-up, power-
down, shutdown, etc.), NMFS does not believe that there will be any
injury or mortality of marine mammals as a result of Shell's
operations.
Comment 15: AEWC states that in making its negligible impact
determination, NMFS failed to consider several impacts: (1) Displacing
marine mammals from feeding areas; (2) non-auditory, physiological
effects, namely stress; (3) the possibility of vessel strikes needs to
be considered in light of scientific evidence of harm from ship traffic
to marine mammals; (4) impacts to marine mammal habitat, including
pollution of the marine environment and the risk of oil spills, toxic,
and nontoxic waste being discharged; (5) impacts to fish and other food
sources upon which marine mammals rely; and (6) specific marine mammals
that will be taken, including their age, sex, and reproductive
condition. The first issue was also raised by Dr. Bain.
Response: NMFS does not agree that these impacts were not
considered. First, the area that would be ensonified by Shell's
proposed open water marine surveys represents a small fraction of the
total habitat of marine mammals in the Beaufort and Chukchi Seas. In
addition, as the survey vessel is constantly moving, the ensonified
zone where the received levels exceed 160 dB re 1 [micro]Pa (rms),
which is estimated to be approximately 7.3 km\2\ at any given time, is
constantly moving. Therefore, the duration during which marine mammals
would potentially avoid the ensonified area would be brief. Therefore,
NMFS does not believe marine mammals would be displaced from their
customary feeding areas as a result of Shell's proposed marine surveys.
Second, non-auditory, physiological effects, including stress, were
analyzed in the Notice of Proposed IHA (75 FR 27708; May 18, 2010). No
single marine mammal is expected to be exposed to high levels of sound
for extended periods based on the size of the airgun array to be used
by Shell and the fact that an animal would need to swim close to,
parallel to, and at the same speed as the vessel to incur several high
intensity pulses. This also does not take into account the mitigation
measures described later in this document.
Third, impacts resulting from vessel strikes and habitat pollution
and impacts to fish were fully analyzed in NMFS' 2010 Final EA for
Shell and Statoil's open water marine and seismic activities (NMFS
2010). Additionally, the proposed IHA analyzed potential impacts to
marine mammal habitat, including prey resources. That analysis noted
that while mortality has been observed for certain fish species found
in extremely close proximity to the airguns, S[aelig]tre and Ona (1996)
concluded that mortality rates caused by exposure to sounds are so low
compared to natural mortality that issues relating to stock recruitment
should be regarded as insignificant.
For the sixth point, please see the response to comment 4. The age,
sex, and reproductive condition must be provided when possible.
However, this is often extremely difficult to predict. Additional
mitigation measures for bowhead cow/calf pairs, such as monitoring the
120-dB radius and requiring shutdown when 4 or more cow/calf pairs
enter that zone, were considered and required for this survey.
Comment 16: AEWC states that in assessing the level of take and
whether it is negligible, NMFS relied on flawed density estimates that
call into question all of NMFS' preliminary conclusions. AEWC states
that density data are lacking or outdated for almost all marine mammals
that may be affected by Shell's operations in the Beaufort and Chukchi
Seas, especially for the fall. AEWC provided a few species specific
examples to show that NMFS failed to utilize the best available
scientific studies in assessing Shell's application. AEWC argues that
NMFS' guess at the number of beluga and bowhead whales relies on a
study from Moore et al. that was published in 2000, that the density of
bowhead whales was derived from limited aerial surveys conducted by
industry operators, and that these estimates are contrary to the best
available scientific information. AEWC also points out that NMFS makes
no mention of the most recent Alaska Marine Mammal Stock Assessment
Report (SAR) which was released this year, and that the Assessment
cites to a 2003 study that documented bowheads ``in the Chukchi and
Bering Seas in the summer'' that are ``thought to be a part of the
expanding Western Arctic stock'' (Angliss and Allen 2009). While a
study published in 2003 still is not a sufficient basis for a 2009
density analysis, this study does show that additional information is
available that indicates that the number of bowhead whales in the
Chukchi may be higher than estimated by NMFS.
Response: As required by the MMPA implementing regulations at 50
CFR 216.102(a), NMFS has used the best scientific information available
in assessing the level of take and whether it is negligible. Although
most of the data NMFS depends on were collected over 10 years (1982-
1991) from aerial surveys offshore of northern Alaska (Moore et al.
2000), these are the best scientific information available for bowhead
and beluga whale density and distribution so far. Since approximately
10 days of Shell's proposed shallow hazards and site clearance surveys
are likely to occur during the fall period when bowheads are migrating
through the Beaufort Sea, more conservative estimates were made to take
account for this 10-day moving average presented by Richardson and
Thomson (2002). Additionally, the 2003 study noted by AEWC in the
bowhead whale Alaska Marine Mammal SAR discusses distribution, not
density (Rugh et al. 2003). It was not cited because it is not useful
for deriving density estimates.
[[Page 49720]]
Therefore, density estimates for bowhead and beluga whales using Moore
et al. (2000) are based on the best available science.
Comment 17: AEWC states that NMFS fails to explain how and why it
reaches various conclusions in calculating marine mammal densities and
what the densities are actually estimated to be once calculated. One
example is NMFS' reliance on Moore et al. (2000) in making its density
determinations. This study documented sightings of marine mammals but
did not estimate the total number of animals present. AEWC states that
NMFS's practices have resulted in entirely arbitrary calculations of
the level of take of marine mammals and whether such takes constitute
``small numbers'' or a ``negligible impact'' as a result of Shell's
proposal.
Response: All densities used in calculating estimated take of
marine mammals based on the described operations are shown in Tables 6-
1 to 6-3 of Shell's application. Moore et al. (2000) provides line
transect effort and sightings from aerial surveys for cetaceans in the
Chukchi Sea. The kilometers of ``on-transect'' observer effort and
number of sightings were used in the accepted line-transect density
estimate equation described in Buckland et al. (2001). Species specific
correction factors for animals that were not at the surface or that
were at the surface but were not sighted [g(0)] and animals not sighted
due to distance from the survey trackline [f(0)] used in the equation
were taken from reports or publications on the same species or similar
species if no values were available for a given species, that used the
same survey platform. Additional explanations regarding the
calculations of marine mammal densities are provided in the Shell's
application and the Federal Register notice for the proposed IHA (75 FR
27708; May 18, 2010). Therefore, NMFS believes the methodology used in
calculations of the level of take of marine mammals is scientifically
well supported.
Comment 18: AEWC is opposed to NMFS using ``survey data'' gathered
by industry while engaging in oil and gas related activities and
efforts to document their take of marine mammals. AEWC points out that
such industry ``monitoring'' is designed to document the level of take
occurring from the operation (see 75 FR 27724 and Shell's 4MP). AEWC
argues that putting aside whether the methodologies employed are
adequate for this purpose, they certainly are not adequate for
assessing the density or presence of marine mammals that typically
avoid such operations.
Response: In making its determinations, NMFS uses the best
scientific information available, as required by the MMPA implementing
regulations. For some species, density estimates from sightings
surveys, as well as from ``industry surveys'', were provided in the
text of Shell's application and the Notice of Proposed IHA for purposes
of comparison. However, where information was available from sightings
surveys (e.g., Moore et al. 2000; Bengtson et al. 2005), those
estimates were used to calculate take. Data collected on industry
vessels were only used when no other information was available.
Additionally, while some Arctic marine mammal species have shown
fleeing responses to seismic airguns, data is also collected on these
vessels during periods when no active seismic data collection is
occurring.
Comment 19: AEWC states that as a general matter, when it comes to
NMFS assessing the various stocks of marine mammals under the MMPA, it
cannot use outdated data i.e., ``abundance estimates older than 8
years'' because of the ``decline in confidence in the reliability of an
aged abundance estimate'' (Angliss and Allen 2009) and the agency is
thus unable to reach certain conclusions. Similarly, here, where data
are outdated or nonexistent, NMFS should decide it cannot reach the
necessary determinations. AEWC argues that these flaws in NMFS'
analysis render the agency's preliminary determinations about the level
of harassment and negligible impacts completely arbitrary.
Response: The statements quoted by AEWC from Angliss and Allen
(2009) are contained in species SARs where abundance estimates are
older than 8 years. However, the full statement reads as follows:
``However, the 2005 revisions to the SAR guidelines (NMFS 2005) state
that abundance estimates older than 8 years should not be used to
calculate PBR due to a decline in confidence in the reliability of an
aged abundance estimate.'' Shell's activities are not anticipated to
remove any individuals from the stock or population. Therefore, a
recent estimate of PBR is not needed for NMFS to make the necessary
findings under Section 101(a)(5)(D) of the MMPA. Additionally, Shell's
application provides information (including data limitations) and
references for its estimates of marine mammal abundance. Because AEWC
has not provided information contrary to the data provided by Shell,
and NMFS does not have information that these estimates are not
reliable, NMFS considers these data to be the best available.
Comment 20: AWL argues that the effects of ice gouge and strudel
scour surveying should be considered. AWL states that NMFS' dismissal
of potential effects based on marine mammal hearing is not adequately
supported. AWL and Dr. Bain argue that NMFS' approach fails to take
into consideration the fact that: (1) Juvenile whales, based on their
smaller size, likely hear sounds of higher frequencies than adults of
the same species; (2) that sound sources contain frequencies beyond the
``normal'' frequency in the form of undertones, overtones, distortion,
or noise; (3) NMFS failed to consider the beat frequency, that when a
source simultaneously emits sound of more than one frequency, it will
also emit energy at the difference between the two frequencies; (4)
NMFS fails to take into account the fact that information about hearing
abilities of bowhead whales is based on estimates since bowheads have
not been the subject of direct testing and there is inherent
uncertainty in these estimates; and (5) the Federal Register notice
does not address the fact that toothed whales are sensitive to high-
frequency sounds including those over 100 kHz.
Response: NMFS considered the potential effects of Shell's proposed
ice gouge and strudel scour surveys in the Beaufort and Chukchi Seas
(75 FR 27708; May 18, 2010). The reason NMFS does not think take of
marine mammal is likely from ice gouge and strudel scour is because the
active acoustic devices being used in these surveys are either in the
frequency range above 180 kHz, which is beyond marine mammals
functional hearing range, or with low source levels. In addition, due
to their high-frequency nature, there is much absorption during sound
propagation, which weakens much of the acoustic intensity within a
relatively short range.
Although NMFS recognizes much scientific information is still
needed on marine mammal hearing capability and audiograms, studies over
the past sixty years on key common species across several major
taxonomy groups have provided overall hearing ranges of marine mammal
species (see review in Richardson et al. 1995; Southall et al. 2007).
These studies show that marine mammal hearing ranges follow certain
patterns and can be divided into five functional hearing groups: low-
frequency cetacean (baleen whales), mid-frequency cetacean (mostly
large to mid-size toothed whales, and delphinids), high-frequency
cetacean (porpoises and river dolphins),
[[Page 49721]]
pinniped in water, and pinniped in air (Southall et al. 2007). Although
it is possible that juvenile animals could have better hearing at high-
frequency ranges similar to humans, however, the overall sensitivity
that defines hearing is based on species (or hearing groups) instead of
age groups. Therefore, it is incorrect to assume that juvenile whales
hear sounds of higher frequencies because of their small size,
regardless of species and functional hearing groups. In addition, the
reason that juvenile animals (including humans) have slightly better
high-frequency hearing is related to age rather than size (the
principle behind it is a biological phenomenon called presbycusis, or
aging ear).
Regarding point (2) concerning ``normal'' frequency, which was not
defined in the comment, NMFS assumes that Dr. Bain refers to the
frequenc(ies) outside the manufacturers' specs for their acoustic
devices. Although these outlier noises could be a concern for high-
frequency acoustic sources, especially if the frequencies are within
the sensitive hearing range of marine mammals, NMFS does not believe
these noises have high acoustic intensities in most cases.
Nevertheless, NMFS requested that Shell provide frequency spectra and
source characteristics for all of its acoustic devices. Shell reported
back that it was unable to obtain such specifications from
manufacturers. However, Shell will be required to conduct measurements
of power density spectra (frequency spectra) of its high frequency
active acoustic sources (operating frequency >180 kHz) that will be
used in its marine surveys against ambient background noise levels. The
power density spectra of these high frequency active acoustic sources
will be reported in 1/3-octave band and 1-Hz band from 10 Hz to 180
kHz. The purpose for this measurement is to determine whether there is
any acoustic energy within marine mammal hearing ranges that would be
generated from operating these high frequency acoustic sources.
If significant acoustic energy (broadband source level >160 dB re 1
[mu]Pa @ 1 m in frequency band below 180 kHz) from these high frequency
active acoustic sources exists within marine mammal hearing ranges,
Shell is required to implement mitigation measures (such as
establishing disturbance zones). Therefore, NMFS believes it unlikely
that a marine mammal would be taken by this activity.
In regard to point (3), in order to produce ``beat frequency,'' not
only do the two sources have to be very close to each other, they also
have to be perfectly synchronized. In the case of Shell's high-
frequency sonar, these two interfering frequencies will need to be
produced by one device to use the non-linearity of water to
purposefully generate the different frequency between two high
frequencies. Even so, it is a very inefficient way to generate the beat
frequency, with only a low percentage of the original intensity with
very narrow beamwidth. Therefore, NMFS does not consider this to be an
issue of concern.
NMFS is aware that no direct measurements of hearing exist for
these animals, and theories regarding their sensory capabilities are
consequently speculative (for a detailed assessment by species using
the limited available information, see Erbe 2002). In these species,
hearing sensitivity has been estimated from behavioral responses (or
lack thereof) to sounds at various frequencies, vocalization
frequencies they use most, body size, ambient noise levels at the
frequencies they use most, and cochlear morphometry and anatomical
modeling (Richardson et al. 1995; Wartzok and Ketten 1999; Houser et
al. 2001; Erbe 2002; Clark and Ellison 2004; Ketten et al. 2007).
Though detailed information is lacking on the species level, the
combined information strongly suggests that mysticetes are likely most
sensitive to sound from perhaps tens of Hz to ~10 kHz (Southall et al.
2007). Although hearing ranges for toothed whales (mid- and high-
frequency cetaceans) fall between 100s Hz to over 100 kHz, their most
sensitive frequency lie between 10 to 90 kHz, and sensitivity falls
sharply above 100 kHz.
Comment 21: Dr. Bain states that changes in behavior resulting from
noise exposure could lead to indirect injury in marine mammals in the
wild. He presented several examples to suggest that marine mammals
repeatedly exposed to Level B harassment could result in Level A takes:
(1) Harbor porpoise were observed traveling at high speeds during
exposure to mid-frequency sonar in Haro Strait in 2003 and that
exhaustion from rapid flight could lead to mortality; (2) citing MMS'
(2004) Environmental Assessment on Proposed Oil and Gas Lease Sale 195
in the Beaufort Sea Planning Area (OCS EIS/EA MMS 2004-028) that
feeding requires a prey density of 800 mg/m\3\ and his own observation,
Dr. Bain is concerned displacement from highly productive feeding areas
would negatively affect individual whales and that small cetaceans such
as harbor porpoise would face a risk of death if they are unable to
feed for periods as short as 48-72 hours, or they may move into habitat
where they face an increased risk of predation; and (3) individual
killer whales have been observed splitting from their pod when
frightened by sonar and that other killer whales' separation from their
social units has resulted in death.
Response: NMFS agrees that it is possible that changes in behavior
or auditory masking resulting from noise exposure could lead to injury
in marine mammals under certain circumstances in the world, such as
those examples/hypotheses raised by Dr. Bain. However, the assumption
that Dr. Bain made that ``exhaustion from rapid flight leading to heart
or other muscle damage'' could account for mortality merely because of
exposure to airgun noise has no scientific basis. Also, it is not
likely that received SPLs from the site clearance and shallow hazards
surveys would cause drastic changes in behavior or auditory masking in
marine mammals in the vicinity of the action area. First, marine
mammals in the aforementioned examples and hypotheses were exposed to
high levels of non-pulse intermittent sounds, such as military sonar,
which has been shown to cause flight activities (e.g., Haro Strait
killer whales); and continuous sounds such as the vessel, which could
cause auditory masking when animals are closer to the source. The
sources produced by the acoustic equipment and airguns for Shell's site
clearance and shallow hazards surveys are impulse sounds used in
seismic profiling, bathymetry, and seafloor imaging. Unlike military
sonar, seismic pulses have an extremely short duration (tens to
hundreds of milliseconds) and relatively long intervals (several
seconds) between pulses. Therefore, the sound energy levels from these
acoustic sources and small airguns are far lower in a given time
period. Second, the intervals between each short pulse would allow the
animals to detect any biologically significant signals, and thus avoid
or prevent auditory masking. Although airgun pulses at long distances
(over kilometers) may be ``stretched'' in duration and become non-pulse
due to multipath propagation, the intervals between the non-pulse
noises would still allow biologically important signals to be detected
by marine mammals. Especially due to the relatively small source being
used for the site clearance and shallow hazard surveys, the received
levels at such long distances would be even lower (e.g., modeled
received levels at 15 km are expected to be under 120 dB re 1 [mu]Pa).
In addition, NMFS requires mitigation measures to ramp-up acoustic
sources at a rate of no more than 6 dB per 5 min.
[[Page 49722]]
This ramp-up would prevent marine mammals from being exposed to high
level noises without warning, thereby eliminating the possibility that
animals would dramatically alter their behavior (i.e. from a
``startle'' reaction). NMFS also believes that long-term displacement
of marine mammals from a feeding area is not likely because the seismic
vessel is constantly moving, and the maximum 160-dB ensonified radius
is about 1.22 km, which would create an area of ensonification of
approximately 7.3 km\2\ at any given moment, which constitutes a very
small portion of the Beaufort Sea (0.0016 percent). In reality, NMFS
expects the 160-dB ensonified zone to be smaller due to absorption and
attenuation of acoustic energy in the water column.
Comment 22: Citing research on long term adverse effects to whales
and dolphins from whale watching activities (Trites and Bain 2000; Bain
2002; Lusseau et al. 2009), Dr. Bain states that Level B behavioral
harassment could be the primary threat to cetacean populations.
Response: Although NMFS agrees that long-term, persistent, and
chronic exposure to Level B harassment could have a profound and
significant impact on marine mammal populations, such as described in
the references cited by Dr. Bain, those examples do not reflect the
impacts of seismic surveys to marine mammals for Shell's project.
First, whale watching vessels are intentionally targeting and making
close approaches to cetacean species so the tourists onboard can have a
better view of the animals. Some of these whale/dolphin watching
examples cited by Dr. Bain occurred in the coastal waters of the
Northwest Pacific between April and October and for extended periods of
time (``[r]ecreational and scientific whale watchers were active by
around 6 a.m., and some commercial whale watching continued until
around sunset''). Thus multiple vessels have been documented to be in
relatively close proximity to whales for about 12 hours a day, six
months a year, not counting some ``out of season'' whale watching
activities and after dark commercial filming efforts. In addition,
noise exposures to whales and dolphins from whale watching vessels are
probably significant due to the vessels' proximity to the animals. To
the contrary, Shell's proposed open-water shallow hazard and site
clearance surveys, along with existing industrial operations in the
Arctic Ocean, do not intentionally approach marine mammals in the
project areas. Shell's survey locations are situated in a much larger
Arctic Ocean Basin, which is far away from most human impacts.
Therefore, the effects from each activity are remote and spread farther
apart, as analyzed in NMFS' 2010 EA, as well as the MMS 2006 PEA.
Shell's site clearance and shallow hazards activities would only be
conducted between July and October for 60 days, weather permitting. In
addition, although studies and monitoring reports from previous seismic
surveys have detected Level B harassment of marine mammals, such as
avoidance of certain areas by bowhead and beluga whales during the
airgun firing, no evidence suggests that such behavioral modification
is biologically significant or non-negligible (Malme et al. 1986; 1988;
Richardson et al. 1987; 1999; Miller et al. 1999; 2005), as compared to
marine mammals exposed to chronic sound from whale watching vessels, as
cited by Dr. Bain. Therefore, NMFS believes that potential impacts to
marine mammals in the Chukchi Sea by site clearance and shallow hazards
surveys would be limited to Level B harassment only, and due to the
limited scale and remoteness of the project in relation to a large
area, such adverse effects would not accumulate to the point where
biologically significant effects would be realized.
Comment 23: Dr. Bain notes that NMFS uses different thresholds for
continuous and pulsed sounds. Dr. Bain thus assumes that the motivation
for this was to tie impact to SEL measurements of sound (as opposed to
RMS or peak-to-peak measurements), which correlated well with TTS. Dr.
Bain states that there is no evidence linking SEL to behavioral
changes, and citing his paper (Bain and Williams, in review), Mr. Bain
claims he found peak-to-peak level measurements correlated best with
behavioral changes.
Response: First, Dr. Bain's assumption regarding NMFS' use of
different behavioral thresholds for impulse and non-impulse noises are
incorrect. The reason for the difference is not to tie impact to SEL
measurements of sound to behavioral change, rather, this difference
(received level at 160 dB re 1 [mu]Pa for pulse and 120 dB re 1 [mu]Pa
for non-pulse) came from many field observations and analyses (see
review by Richardson et al. 1995; Southall et al. 2007) on measured
avoidance responses in whales in the wild. Specifically, the 160 dB re
1 [mu]Pa (rms) threshold was derived from data for mother-calf pairs of
migrating gray whales (Malme et al. 1983; 1984) and bowhead whales
(Richardson et al. 1985; Richardson et al. 1986) responding when
exposed to seismic airguns (impulsive sound source). The 120 dB re
1[mu]Pa (rms) threshold also originates from research on baleen whales,
specifically migrating gray whales (Malme et al. 1984; predicted 50%
probability of avoidance) and bowhead whales reacting when exposed to
industrial (i.e., drilling and dredging) activities (non-impulsive
sound source) (Richardson et al. 1990).
Dr. Bain's attached paper (Bain and Williams, in review) reports
the results of an examination of effects of large airgun arrays on
behavior of marine mammals in the waters of British Columbia, Canada
and Washington State, USA, using a small boat to monitor out to long
ranges (1 to > 70 km from the seismic source vessel). The paper
concludes that a significant relationship was observed between the
magnitude of behavioral response and peak-to-peak received level and
the long distances at which behavioral responses were observed (> 60 km
for harbor porpoise), along with counter-productive behavior that
occasionally brought individuals into higher-intensity acoustic zones.
However, there are potential design flaws in the study. First, the
paper states a launch carried aboard the seismic receiver vessel was
placed in the water to perform received level measurements near marine
mammals. When making acoustic measurements, the launch ``travelled
along a line at approximately 20 km/h until either marine mammals were
closely approached, or the launch had travelled 10 km.'' Therefore, it
is highly likely that behavioral reactions from observed marine mammals
were caused by the high-speed, close-approach of the launch, rather
than from distant seismic airguns. This experiment design may explain
the authors' observation of ``counter-productive behavioral responses''
that animals are moving into higher-intensity acoustic zones, which
probably indicates that behavioral changes caused by Bain's launch
greatly exceeded any behavioral change resulting from exposure to
seismic airgun noise. Second, the authors of the paper also expressed
``methodological concerns due to the subjectivity of observers.''
Nevertheless, this study concludes that harbor seal individuals were
generally moving away from the airguns at exposure levels above 170 dB
re 1 [mu]Pa (p-p) and that gray whales were observed at received levels
up to approximately 170 dB re 1 [mu]Pa (p-p) exhibiting no obvious
behavioral response. These observations contradict Mr. Bain's earlier
comments that major behavioral effects result from noise in the 105-125
dB range.
Finally, Bain and Williams (in review) also state that the study
``found that while airguns concentrated their sound output at low
frequencies, substantial
[[Page 49723]]
high frequency energy (to at least 100 kHz) was also present.''
However, the paper provides no explanation as to how this conclusion
was made. The accompanying power density spectrum (Figure 2 in Bain and
Williams, in review) of the paper fails to show evidence that the
frequencies above 1 kHz were mostly contributed from seismic airguns,
and there was no indication at what distance this recording was made.
Subsistence Issues
Comment 24: AEWC states that the nondiscretionary congressional
directive that there will be no more than a negligible impact to marine
mammals and no unmitigable adverse impact to the availability of marine
mammals for subsistence taking is consistent with the MMPA's overall
treatment of both marine mammal and subsistence protections. AEWC
further states that Congress has set a ``moratorium on the taking * * *
of marine mammals,'' 16 U.S.C. 1371(a), with the sole exemption
provided for the central role of subsistence hunting by Alaska Natives.
Thus, AEWC concludes that Congress has given priority to subsistence
takes of marine mammals over all other exceptions to the moratorium,
which may be applied for and obtained only if certain statutory and
regulatory requirements are met. However, AEWC states that incidental
harassment authorizations are available only for specified activities
for which the Secretary makes the mandated findings. Thus, the pursuit
of those activities is subordinated, by law, to the critical
subsistence uses that sustain Alaska's coastal communities. NSB further
states that NMFS has not adequately demonstrated that the proposed
activities will not have ``an unmitigable adverse impact on the
availability of such species or stock for taking for subsistence
uses.''
Response: The MMPA does not prohibit an activity from having an
adverse impact on the availability of marine mammals for subsistence
uses; rather, the MMPA requires NMFS to ensure the activity does not
have an unmitigable adverse impact on the availability of such species
or stocks for taking for subsistence uses. NMFS has defined
``unmitigable adverse impact'' in 50 CFR 216.103 as an impact resulting
from the specified activity: (1) That is likely to reduce the
availability of the species to a level insufficient for a harvest to
meet subsistence needs by: (i) Causing the marine mammals to abandon or
avoid hunting areas; (ii) directly displacing subsistence users; or
(iii) placing physical barriers between the marine mammals and the
subsistence hunters; and (2) that cannot be sufficiently mitigated by
other measures to increase the availability of marine mammals to allow
subsistence needs to be met.
For the determination of the unmitigable adverse impact analysis,
NMFS, other government agencies, and affected stakeholder agencies and
communities were provided a copy of the draft POC in March 2010, which
outlined measures Shell would implement to ensure no unmitigable
adverse impact to subsistence uses. The POC specifies times and areas
to avoid in order to minimize possible conflicts with traditional
subsistence hunts by North Slope villages for transit and open-water
activities. Shell waited to begin activities until the close of the
spring beluga hunt in the village of Point Lay. Shell has also
developed a Communication Plan and will implement the plan before
initiating the 2010 program to coordinate activities with local
subsistence users as well as Village Whaling Associations in order to
minimize the risk of interfering with subsistence hunting activities,
and keep current as to the timing and status of the bowhead whale
migration, as well as the timing and status of other subsistence hunts.
The Communication Plan includes procedures for coordination with
Communication and Call Centers to be located in coastal villages along
the Beaufort and Chukchi Seas during Shell's program in 2010.
Based on the measures contained in the IHA (and described later in
this document), NMFS has determined that mitigation measures are in
place to ensure that Shell's operations do not have an unmitigable
adverse impact on the availability of marine mammal species or stocks
for subsistence uses.
Mitigation and Monitoring Concerns
Comment 25: NSB is concerned that MMOs cannot see animals at the
surface when it is dark or during the day because of fog, glare, rough
seas, the small size of animals such as seals, and the large portion of
time that animals spend submerged. NSB also notes that Shell has
acknowledged that reported sightings are only ``minimum'' estimates of
the number of animals potentially affected by surveying.
Response: NMFS recognizes the limitations of visual monitoring in
darkness and other inclement weather conditions. Therefore, in the IHA
to Shell, NMFS requires that no seismic airgun can be ramped up when
the entire safety zones are not visible. However, Shell's operations
will occur in an area where periods of darkness do not begin until
early September. Beginning in early September, there will be
approximately 1-3 hours of darkness each day, with periods of darkness
increasing by about 30 min each day. By the end of the survey period,
there will be approximately 8 hours of darkness each day. These
conditions provide MMOs favorable monitoring conditions for most of the
time.
Comment 26: AEWC notes that Shell intends to employ marine mammal
observers (``MMO'') and a ``190 and 180 dB safety radii for pinnipeds
and cetaceans, respectively, and the 160 dB disturbance radii'' to
mitigate these effects. However, AEWC states that the safety radii
proposed by Shell do not negate these impacts. The safety radii only
function as well as the observers on the vessels can see and report
marine mammals within the radii or the general vicinity of the vessel.
AEWC notes that MMOs are human and suffer from human flaws, and that
observers are bad at judging distances in the water--i.e., whether a
marine mammal is within the radii or not. AEWC further states that at
night and during storms MMOs are particularly ineffective. Thus, AEWC
concludes that Shell's proposed MMO program is not sufficient
mitigation to prevent Shell from engaging in Level A harassment.
Response: NMFS does not agree with AEWC's observation and
conclusion, although AEWC is right that distance judging in the water
is a challenging issue for MMOs. However, as noted in Shell's Marine
Mammal Monitoring and Mitigation Plan (4MP), distances to nearby marine
mammals will be estimated with binoculars (Fujinon 7 x 50) containing a
reticle to measure the vertical angle of the line of sight to the
animal relative to the horizon. In addition, MMOs may use a laser
rangefinder to test and improve their abilities for visually estimating
distances to objects in the water. The device was very useful in
improving the distance estimation abilities of the observers at
distances up to about 600 m (1,968 ft)--the maximum range at which the
device could measure distances to highly reflective objects such as
other vessels--while the isopleth to the 180 dB received level is
expected to be at 125 m (410 ft) from the source vessel. Therefore,
NMFS believes that marine mammal monitoring efforts that would be
employed by Shell during its marine surveys are adequate.
In addition, mitigation measures such as ramp-up of airguns would
warn any marine mammals that are missed during the pre-survey period to
leave the survey vicinity. Lastly, recent studies show that it is
unlikely a marine
[[Page 49724]]
mammal would experience TTS when exposed to a seismic pulse at a
received level of 190 dB (see Finneran et al. 2002). In order for a
marine mammal to experience even a mild TTS, the animal has to be in a
zone with intense noise for a certain duration to and be exposed to a
sound level much greater than a single seismic impulse, and research on
marine mammal behavior during TTS experiments indicates that animals
will try to avoid areas where receive levels are high enough to cause
TTS (see Finneran et al. 2002).
Comment 27: NSB and AEWC note that Shell asserts that mitigation
measures are designed to protect animals from injurious takes, but it
is not clear that these mitigation measures are effective in protecting
marine mammals or subsistence hunters. AEWC states that data previously
presented by Shell and ConocoPhillips from their seismic activities
made clear that MMOs failed to detect many marine mammals that
encroached within the designated safety zones. AEWC further notes that
Shell admits that night vision devices ``are not nearly as effective as
visual observation during daylight hours.''
Response: NMFS believes that the required monitoring and mitigation
measures are effective and are an adequate means of effecting the least
practicable impact to marine mammals and their habitat. Moreover, the
safety zones for Shell's 2010 surveys are much smaller than those for
the larger 3D seismic surveys in past years. The 180- and 190-dB safety
zones are 125 m (410 ft) and 35 m (115 ft), respectively. The
monitoring reports from 2006, 2007, 2008, and 2009 do not note any
instances of serious injury or mortality (Patterson et al. 2007; Funk
et al. 2008; Ireland et al. 2009; Reiser et al. 2010). Additionally,
the fact that a power-down or shutdown is required does not indicate
that marine mammals are not being detected or that they are incurring
serious injury. As discussed elsewhere in this document and in the
Notice of Proposed IHA (75 FR 27708; May 18, 2010), the received level
of a single seismic pulse (with no frequency weighting) might need to
be approximately 186 dB re 1 [mu]Pa\2\-s (i.e., 186 dB sound exposure
level [SEL]) in order to produce brief, mild TTS (a non-injurious,
Level B harassment) in odontocetes. Exposure to several strong seismic
pulses that each have received levels near 175-180 dB SEL might result
in slight TTS in a small odontocete, assuming the TTS threshold is (to
a first approximation) a function of the total received pulse energy.
For Shell's proposed survey activities, the distance at which the
received energy level (per pulse) would be expected to be >=175-180 dB
SEL is the distance to the 190 dB re 1 [mu]Pa (rms) isopleth (given
that the rms level is approximately 10-15 dB higher than the SEL value
for the same pulse). Seismic pulses with received energy levels >=175-
180 dB SEL (190 dB re 1 [mu]Pa (rms)) are expected to be restricted to
a radius of approximately 35 m (115 ft) around the airgun array.
For baleen whales, there are no data, direct or indirect, on levels
or properties of sound that are required to induce TTS. The frequencies
to which baleen whales are most sensitive are lower than those to which
odontocetes are most sensitive, and natural background noise levels at
those low frequencies tend to be higher. As a result, auditory
thresholds of baleen whales within their frequency band of best hearing
are believed to be higher (less sensitive) than are those of
odontocetes at their best frequencies (Clark and Ellison 2004). From
this, it is suspected that received levels causing TTS onset may also
be higher in baleen whales.
In pinnipeds, TTS thresholds associated with exposure to brief
pulses (single or multiple) of underwater sound have not been measured.
Initial evidence from prolonged exposures suggested that some pinnipeds
may incur TTS at somewhat lower received levels than do small
odontocetes exposed for similar durations (Kastak et al. 1999; 2005).
However, more recent indications are that TTS onset in the most
sensitive pinniped species studied (harbor seal, which is closely
related to the ringed seal) may occur at a similar SEL as in
odontocetes (Kastak et al. 2004).
NMFS concluded that cetaceans and pinnipeds should not be exposed
to pulsed underwater noise at received levels exceeding, respectively,
180 and 190 dB re 1 [mu]Pa (rms). The established 180- and 190-dB re 1
[mu]Pa (rms) criteria are not considered to be the levels above which
TTS might occur. Rather, they are the received levels above which, in
the view of a panel of bioacoustics specialists convened by NMFS before
TTS measurements for marine mammals started to become available, one
could not be certain that there would be no injurious effects, auditory
or otherwise, to marine mammals. As summarized above, data that are now
available imply that TTS is unlikely to occur unless bow-riding
odontocetes are exposed to airgun pulses much stronger than 180 dB re 1
[mu]Pa rms (Southall et al. 2007). No cases of TTS are expected as a
result of Shell's proposed activities given the small size of the
source, the strong likelihood that baleen whales (especially migrating
bowheads) would avoid the approaching airguns (or vessel) before being
exposed to levels high enough for there to be any possibility of TTS,
and the mitigation measures proposed to be implemented during the
survey described later in this document.
There is no empirical evidence that exposure to pulses of airgun
sound can cause PTS in any marine mammal, even with large arrays of
airguns (see Southall et al. 2007). PTS might occur at a received sound
level at least several decibels above that inducing mild TTS if the
animal is exposed to the strong sound pulses with very rapid rise time.
It is highly unlikely that marine mammals could receive sounds
strong enough (and over a sufficient duration) to cause permanent
hearing impairment during a project employing the airgun sources
planned here (i.e., an airgun array with a total discharge volume of 40
in\3\). In the proposed project, marine mammals are unlikely to be
exposed to received levels of seismic pulses strong enough to cause
more than slight TTS. Given the higher level of sound necessary to
cause PTS, it is even less likely that PTS could occur. In fact, even
the levels immediately adjacent to the airgun may not be sufficient to
induce PTS, especially because a mammal would not be exposed to more
than one strong pulse unless it swam immediately alongside the airgun
for a period longer than the inter-pulse interval. Baleen whales, and
belugas as well, generally avoid the immediate area around operating
seismic vessels. The planned monitoring and mitigation measures,
including visual monitoring, power-downs, and shutdowns of the airguns
when mammals are seen within the safety radii, will minimize the
already-minimal probability of exposure of marine mammals to sounds
strong enough to induce PTS.
NMFS acknowledges that night-time monitoring by using night vision
devices is not nearly as effective as visual observation during
daylight hours. Therefore, the IHA to Shell prohibits start up of
seismic airguns when the entire safety zone can not be effectively
monitored during the night-time hours. If Shell has a shutdown of its
seismic airgun array during low-light hours, it will have to wait till
daylight to start ramping up the airguns.
Comment 28: The Commission believes that absent an evaluation by
the oil and gas industry of its monitoring and mitigation measures, the
effects of the industry's activities will remain uncertain. The
Commission recommends that NMFS require Shell to collect information
necessary to evaluate the effectiveness of the
[[Page 49725]]
mitigation measures adopted and to review and modify mitigation
measures accordingly. The Commission notes that mitigation measures
required for Shell's proposed marine surveys should be useful to a
degree, but in some cases they are not sufficiently specific. For
example, the Commission raised questions about the ``power-down'' and
asks NMFS to specify what speed of reduction would be required when a
marine mammal is observed within 274 m (300 yards) of a vessel. The
Commission considers it vital that NMFS and the industry make every
reasonable effort to evaluate the mitigation measures whenever
possible, and that the evaluation should provide a basis for (1)
Distinguishing between measures that do and do not have protective
value, (2) improving those that are useful, and (3) finding
alternatives for those that are not. Citing a report from the Joint
Subcommittee on Ocean Science and Technology, NSB also questions the
effectiveness of ramp-up measures.
Response: In order to issue an incidental take authorization (ITA)
under Sections 101(a)(5)(A) and (D) of the MMPA, NMFS must, where
applicable, set forth the permissible methods of taking pursuant to
such activity, and other means of effecting the least practicable
impact on such species or stock and its habitat, paying particular
attention to rookeries, mating grounds, and areas of similar
significance, and on the availability of such species or stock for
taking for certain subsistence uses (where relevant). For Shell's
proposed open water marine surveys, a series of mitigation and
monitoring measures are required under the IHA. These mitigation
measures include: (1) Sound source measurements to determine safety
zones more accurately, (2) establishment of safety and disturbance
zones to be monitored by MMOs on the seismic vessel, (3) a power-down
when a marine mammal is detected approaching a safety zone and a
shutdown when a marine mammal is observed within a zone, (4) ramp-up of
the airgun array, (5) establishing a 120-dB safety zone and prohibition
of seismic surveys within that zone whenever it encompasses four or
more bowhead whale mother-calf pairs, (6) establishing a 160-dB safety
zone that would prohibit firing of the seismic airguns within the zone
whenever it encompasses 12 or more bowhead or gray whales involved in
non-migratory behavior (e.g., feeding), and (7) a requirement that
vessels reduce speed when within 274 m (300 yards) of whales and steer
around those whales if possible.
The basic rational for these mitigation measures is (a) To avoid
exposing marine mammals to intense seismic airgun noises at received
levels that could cause TTS (for mitigation measures listed as (1)
through (4)), (b) to avoid exposing large aggregations of bowhead
whales and bowhead whale calves to elevated noise received levels
(mitigation measures (5) and (6)), and (c) to avoid vessel strike of
marine mammals (mitigation measure (7)). Although limited research in
recent years shows that noise levels that could induce TTS in
odontocetes and pinnipeds are much higher than current NMFS safety
thresholds (i.e., 180 dB and 190 dB re 1 [mu]Pa (rms) for cetaceans and
pinnipeds, respectively), mitigation measures listed in (1) through (3)
provide very conservative measures to ensure that no marine mammals are
exposed to noise levels that would result in TTS. The power-down
measure listed in (3) requires Shell to reduce the firing airguns
accordingly so that a marine mammal that is detected approaching the
safety zone will be further away from the reduced safety radius (as a
result of power-down).
Regarding mitigation measures requiring ramp-ups, while scientific
research built around the question on whether ramp-up is effective has
not been conducted, several studies on the effects of anthropogenic
noise on marine mammals indicate that many marine mammals will move
away from a sound source that they find annoying (e.g. Malme et al.
1984; Miller et al. 1999; others reviewed in Richardson et al. 1995).
In particular, three species of baleen whales have been the subject of
tests involving exposure to sounds from a single airgun, which is
equivalent to the first stage of ramp-up. All three species were shown
to move away at the onset of a single airgun operation (Malme et al.
1983; 1984; 1985; 1986; Richardson et al. 1986; McCauley et al. 1998;
2000). From this research, it can be presumed that if a marine mammal
finds a noise source annoying or disturbing, it will move away from the
source prior to sustaining an injury, unless some other over-riding
biological activity keeps the animal from vacating the area. This is
the premise supporting NMFS' and others' belief that ramp-up is
effective in preventing injury to marine mammals. However, to what
degree ramp-up protects marine mammals from exposure to intense noises
is unknown. Thus, NMFS will require industry applicants that will
conduct marine or seismic surveys in the 2010 open water season to
collect, record, analyze, and report MMO observations during any ramp-
up period, as recommended by the independent peer review panel convened
in March 2010, to review Shell's monitoring plan (more information is
available later in this document).
Mitigation measures (5) and (6) regarding four cow-calf pairs and
an aggregation of 12 bowhead and/or gray whales, which were proposed in
MMS' 2006 programmatic EA and were required in NMFS IHAs issued between
2006 to 2008, need to be further analyzed for their effectiveness and
efficacy. NMFS is currently conducting a review of these mitigation
measures through the Environmental Impact Statement process for the
Arctic oil and gas activities.
Finally, regarding the speed reduction for vessels in the vicinity
of marine mammals, NMFS clarifies that vessel speed must be reduced to
less than 10 knots when a marine mammal is detected within 274 m (300
yards) of the vessel. This mitigation measure is to avoid vessel strike
of marine mammals and is based on NMFS' ship strike rule for the north
Atlantic right whale. NMFS will evaluate the efficacy of this
mitigation. Although there has never been a vessel strike of marine
mammals by vessels involved in seismic activities in the Arctic, NMFS
is still taking this precaution.
Comment 29: The Commission recommends that Shell be required to
supplement its mitigation measures by using passive acoustic monitoring
(PAM) to provide a more reliable estimate of the number of marine
mammals taken during the course of the proposed seismic survey.
Response: NMFS' 2010 EA for this action contains an analysis of why
PAM is not required to be used by Shell to implement mitigation
measures. Shell will deploy acoustic recorders to collect data on
vocalizing animals. However, this information will not be used in a
real-time or near-real-time capacity. Along with the fact that marine
mammals may not always vocalize while near the PAM device, another
impediment is that flow noise generated by a towed PAM will interfere
with low frequency whale calls and make their detection difficult and
unreliable. MMS sponsored a workshop on the means of acoustic detection
of marine mammals in November 2009 in Boston, MA. The workshop reviewed
various available acoustic monitoring technology (passive and active),
its feasibility and applicability for use in MMS-authorized activities,
and what additional developments need to take place to
[[Page 49726]]
improve its effectiveness. The conclusion is that at this stage, using
towed passive acoustics to detect marine mammals is not a mature
technology. NMFS may consider requirements for PAM in the future
depending on information received as the technology develops further.
Additionally, NMFS recommended to Shell that the company work to help
develop and improve this type of technology for use in the Arctic.
Comment 30: AWL states that NMFS should consider time and space
limitations on surveying in order to reduce harm, and that there is a
general consensus that spatial-temporal avoidance of high value habitat
represents one of the best means to diminish potential impacts. In this
case, AWL requests NMFS to evaluate the possibility of avoiding
activities during the peak of the bowhead migration within the Beaufort
migratory corridor before issuing an IHA. In addition, AWL requests
NMFS to require Shell to complete its 30 days of shallow hazard
surveying in July and August in an effort to avoid--as much as
possible--the bulk of the bowhead migration.
Response: In making its negligible determination for the issuance
of an IHA to Shell for open water marine surveys, NMFS has conducted a
thorough review and analysis on how to reduce any adverse effects to
marine mammals from the proposed action, including the consideration of
time and space limitations that could reduce impacts to the bowhead
migration. As Shell indicates in its IHA application, the majority of
the site clearance and shallow hazards surveys will be conducted during
August and September to avoid the peak of the bowhead whale migration
through the Beaufort Sea, which typically occurs in mid-September and
October.
In addition, bowhead whales migrating west across the Alaskan
Beaufort Sea in autumn, in particular, are unusually responsive to
airgun noises, with avoidance occurring out to distances of 20-30 km
from a medium-sized airgun source (Miller et al. 1999; Richardson et
al. 1999). However, while bowheads may avoid an area of 20 km (12.4 mi)
around a noise source, when that determination requires a post-survey
computer analysis to find that bowheads have made a 1 or 2 degree
course change, NMFS believes that does not rise to a level of a
``take'' and that such minor behavioral modification is not likely to
be biologically significant.
Comment 31: The Commission recommends that NMFS (1) Review the
proposed monitoring measures to ensure that Shell is required to gather
information on all the potentially important sources of noise and the
complex sound field that the seismic survey activities create; (2) work
with Shell and its contractors to engage acknowledged survey experts to
review the survey design and planned analyses to ensure that Shell will
provide relatively unbiased and reliable results; (3) work with Shell
to coordinate a comparative analysis of the results of vessel-based,
aerial, and passive acoustic monitoring methods to evaluate their
relative strengths and weaknesses and determine if and how they could
be improved for use with future surveys; (4) develop a plan for
collecting meaningful baseline information--that is, information that
provides a reliable basis for evaluating long-term effects on the
marine mammal species and stocks that may be affected by oil and gas
development and production in the Beaufort Sea area; and (5) work with
Shell to determine how the data collected during the proposed
activities can be made available to other scientific purposes.
Response: NMFS largely agrees with the Commission's recommendations
and has been working with the seismic survey applicants and their
contractors on gathering information on acoustic sources, survey design
review, and monitoring analyses. NMFS has contacted Shell and received
information on all the active acoustic sources that would be used for
its proposed open water marine surveys. The information includes source
characteristics such as frequency ranges and source levels, as well as
estimated propagation loss. In addition, at NMFS' request, Shell has
provided power density spectra for all of its high-frequency sonar
equipments.
Regarding the remaining points, NMFS convened an independent peer
review panel to review Shell's 4MP for the Open Water Marine Survey
Program in the Beaufort and Chukchi Seas, Alaska. The panel met on
March 25 and 26, 2010, and provided their final report to NMFS on April
22, 2010. NMFS has reviewed the report and evaluated all
recommendations made by the panel. NMFS has determined that there are
several measures that Shell can incorporate into its 2010 open water
Marine Survey Program 4MP to improve it, and is requiring those
measures in the IHA. Additionally, there are other recommendations that
NMFS has determined would also result in better data collection, and
could potentially be implemented by oil and gas industry applicants,
but which likely could not be implemented for the 2010 open-water
season due to technical issues (see below). A detailed discussion about
the panel review is presented later in this document. While it may not
be possible to implement those changes this year, NMFS believes that
they are worthwhile and appropriate suggestions that may require a bit
more time to implement, and Shell should consider incorporating them
into future monitoring plans should Shell decide to apply for IHAs in
the future. Nevertheless, despite these recommendations, NMFS believes
that Shell's 4MP will be sufficient for purposes of data gathering in
2010.
Comment 32: The Commission recommends that the IHA require Shell to
halt its seismic survey and consult with NMFS regarding any seriously
injured or dead marine mammal when the injury or death may have
resulted from Shell's activities.
Response: NMFS concurs with the Commission's recommendation. NMFS
has included a condition in the IHA which requires Shell to immediately
shutdown the seismic airguns if a dead or injured marine mammal has
been sighted within an area where the seismic airguns were operating
within the past 24 hours so that information regarding the animal can
be collected and reported to NMFS. In addition, Shell must report the
events to the Marine Mammal Stranding Network within 24 hours of the
sighting, as well as to the NMFS staff person designated by the
Director, Office of Protected Resources, or to the staff person
designated by the Alaska Regional Administrator. The lead MMO is
required to complete a written certification, which must include the
following information: species or description of the animal(s); the
condition of the animal(s) (including carcass condition if the animal
is dead); location and time of first discovery; observed behaviors (if
alive); and photographs or video (if available). In the event that the
marine mammal injury or death was determined to have been a direct
result of Shell's activities, then operations will cease, NMFS and the
Stranding Network will be notified immediately, and operations will not
be permitted to resume until NMFS has had an opportunity to review the
written certification and any accompanying documentation, make
determinations as to whether modifications to the activities are
appropriate and necessary, and has notified Shell that activities may
be resumed.
If NMFS determines that further investigation is appropriate, once
investigations are completed and determinations made, NMFS would use
available information to help reduce the
[[Page 49727]]
likelihood that a similar event would happen in the future and move
forward with necessary steps to ensure environmental compliance for oil
and gas related activities under the MMPA.
Cumulative Impact Concerns
Comment 33: NSB, AEWC, ICAS, and AWL state that NMFS must also
consider the effects of disturbances in the context of other activities
occurring in the Arctic. NSB states that NMFS should ascertain the
significance of multiple exposures to underwater noise, ocean
discharge, air pollution, and vessel traffic--all of which could impact
bowhead whales and decrease survival rates or reproductive success. NSB
notes that the cumulative impacts of all industrial activities must be
factored into any negligible impact determination. NSB, AEWC, ICAS, and
AWL list a series of reasonably foreseeable activities in the Arctic
Ocean as: (1) GX Technology's Beaufort Sea seismic surveys; (2)
Statoil's Chukchi Sea seismic surveys; (3) Seismic surveys planned in
the Canadian Arctic; (4) U.S. Geological Survey's (USGS') seismic
surveys; (5) BP's production operations at Northstar; and (6)
Dalmorneftegeophysica (DMNG) Russian Far East offshore seismic surveys.
Response: Under section 101(a)(5)(D) of the MMPA, NMFS is required
to determine whether the taking by the applicant's specified activity
will take only small numbers of marine mammals, will have a negligible
impact on the affected marine mammal species or population stocks, and
will not have an unmitigable impact on the availability of affected
species or stocks for subsistence uses. Cumulative impact assessments
are NMFS' responsibility under the National Environmental Policy Act
(NEPA), not the MMPA. In that regard, MMS' 2006 Final PEA, NMFS' 2007
and 2008 Supplemental EAs, NMFS' 2009 EA, and NMFS' 2010 EA address
cumulative impacts. The most recent NMFS' 2010 EA addresses cumulative
activities and the cumulative impact analysis focused on oil and gas
related and non-oil and gas related activities in both Federal and
State of Alaska waters that were likely and foreseeable. The oil and
gas related activities in the U.S. Arctic in 2010 include this
activity; Statoil's proposed seismic survey in Chukchi Sea; ION
Geophysical's proposed seismic survey in Beaufort Sea; and BP's
production operations at Northstar. GX Technology's Beaufort Sea
seismic surveys have been cancelled by the company. Seismic survey
activities in the Canadian and Russian Arctic occur in different
geophysical areas, therefore, they are not analyzed under the NMFS 2010
EA. Other appropriate factors, such as Arctic warming, military
activities, and noise contributions from community and commercial
activities were also considered in NMFS' 2010 EA. Please refer to that
document for further discussion of cumulative impacts.
Comment 34: Citing the peer review panel created for this year's
open water meeting that Shell's activities ``will create a complex
sound field with potential effects beyond those that the applicant
proposes to monitor,'' and NRC's advice on assessing cumulative effects
to the population from multiple effects to multiple individuals, the
AWL recommends NMFS create a sound budget for the Arctic, limiting the
total amount of sound introduced into the water. The AWL further states
that instead of dismissing the impacts of relatively smaller sources of
sound, NMFS should account for and regulate those sources, and a sound
budget may be the most appropriate tool for doing so. The AWL states
that even without a comprehensive sound budget, NMFS could impose
limits on the total number of activities permitted in the Arctic during
the open water season. Allowing only one or two noise generating
activities each year could reduce the potential for take and would
facilitate additional monitoring of the impacts of noise, since
multiple noise sources make it very difficult to study the effect of
specific sound sources.
Response: NMFS agrees that assessing cumulative effects to the
population from multiple effects to multiple individual marine mammals
is an important approach to understanding overall impacts of industry
activities to the species and the environment. NMFS is also considering
the peer review panel's recommendation and is addressing sound budget
issues in the marine environment through a series of workshops and a
working group. In addition, Shell is required to provide sound source
verification (SSV) tests before they start marine surveys. These
acoustic measurements will be analyzed and provided in the 90-day
report for Shell's marine surveys. Additional information on Arctic
sound budget data are being collected by many researchers, including
underwater recordings made by some of the passive acoustic arrays
deployed on the Alaska north slope. These data will hopefully be
analyzed to address overall ambient sound levels and a sound budget for
the Arctic Ocean.
Further, NMFS also requested that Shell provide source
characteristics for all active acoustic sources that are planned to be
used in the proposed open water marine surveys. NMFS has reviewed these
data and analyzed overall ambient sound levels in the Arctic Ocean
based on current knowledge. The review and analysis showed that the
short-term ensonification of a small region in the Beaufort and Chukchi
Seas during the open water season is not likely to appreciably increase
the ambient noise level and alter the local ocean soundscape. A
description of the analysis is provided in NMFS' 2010 EA for Shell and
Statoil's proposed open water marine and seismic surveys (NMFS 2010).
Finally, as NMFS is working on its Arctic EIS, limits on the total
of oil and gas related activities to be allowed in the Arctic are being
considered under separate alternatives. Nevertheless, NMFS does not
agree with AWL's notion of ``[a]llowing only one or two noise
generating activities each year'' as monitoring reports and studies
from prior year industrial activities (e.g., there were five seismic
survey activities in the open water season of 2008) indicate that
multiple activities can be authorized in the Arctic while still
reaching a finding of no significant impact, provided that appropriate
mitigation and monitoring measures are prescribed and implemented.
Comment 35: In addressing cumulative effects, Dr. Bain points out a
number of ways he believes that Statoil's seismic surveys in the
Chukchi Sea could interact with Shell's marine surveys: (1) If the same
individuals are exposed to both projects, this would increase the
duration of exposure beyond those considered in the applications.
Further, individuals would potentially be exposed multiple times, and
multiple exposures are likely to result in increased stress levels; (2)
if both projects operate in the Chukchi at the same time, individuals
would be forced to simultaneously respond to both noise sources.
Avoidance of one noise source could result in a marine mammal
approaching the other noise source, resulting in unexpectedly high
noise exposure. This negates the safety assumption that animals will
move away prior to receiving harmful exposure; and (3) different
individuals may be exposed to the two projects, which would put NMFS'
assumption that its policies only allow small takes to occur into
question.
Response: In assessing the cumulative effects, NMFS has considered
that animals could be exposed to multiple activities, multiple times.
As described in detail in the proposed IHA (75 FR
[[Page 49728]]
27708; May 18, 2010), Shell's ice gouge survey in the Chukchi Sea is
not expected to result in takes of marine mammals due to its high
frequency and the low energy acoustic sources being used. In addition,
even if marine mammals would be affected by the presence of the ice
gouge survey activities being conducted concurrently with Statoil's 3D
marine seismic survey, the affected areas represent a small fraction of
the total habitat of the Chukchi Sea, therefore, it is not likely that
marine mammals avoiding one source would run into the other, as
suggested by Dr. Bain. The ensonified area with received levels above
160 dB in the Chukchi Sea is 531 km\2\ (or 0.089 percent of the entire
Chukchi Sea). Finally, considering different individuals may be exposed
to two projects in both the Beaufort and Chukchi Seas, NMFS has
provided the total number of individuals that could be taken by Level B
harassment from both activities and concludes that the total take
numbers are small, with the most potential takes being: 184 Eastern
Chukchi Sea beluga whales (4.95% of the population), 539 B-C-B bowhead
whales (3.78% population), and 6,629 Alaska ringed seals (2.87%
population). Potential takes of all other species are estimated to be
under 1% of the populations. Therefore, NMFS believes Dr. Bain's
concerns are not warranted.
ESA Concerns
Comment 36: AWL states that NMFS section 7 consultation under the
ESA must consider the potential impact of potential future oil and gas
activities, including (1) Shell's strudel scour and ice gouge surveying
to enable pipeline construction for production on its proposed Chukchi
and Beaufort drill sites; and (2) a shallow hazard survey in Harrison
Bay to allow for later exploration drilling. AWL states that in both
instances, NMFS must consider the effects of the entire agency action.
Response: Under section 7 of the ESA, NMFS Office of Protected
Resources has completed consultation with NMFS Alaska Regional Office
on ``Authorization of Small Takes under the Marine Mammal Protection
Act for Certain Oil and Gas Exploration Activities in the U.S. Beaufort
and Chukchi Seas, Alaska for 2010.'' In a Biological Opinion issued on
July 13, 2010, NMFS concluded that the issuance of the incidental take
authorizations under the MMPA for seismic surveys are not likely to
jeopardize the continued existence of the endangered humpback or
bowhead whale. As no critical habitat has been designated for these
species, none will be affected. The 2010 Biological Opinion takes into
consideration all oil and gas related seismic survey activities that
would occur in the 2010 open water season. This Biological Opinion does
not include impacts from exploratory drilling and production
activities, which are subject to a separate consultation. In addition,
potential future impacts from oil and gas activities will be subject to
consultation in the future when activities are proposed. NMFS has
reviewed Shell's proposed action and has determined that the findings
in the 2010 Biological Opinion apply to its 2010 Beaufort Sea site
clearance and shallow hazards surveys. In addition, NMFS has issued an
Incidental Take Statement (ITS) under this Biological Opinion for
Shell's survey activities, which contains reasonable and prudent
measures with implementing terms and conditions to minimize the effects
of take of bowhead and humpback whales.
Comment 37: AWL argues that NMFS' existing regional biological
opinion is inadequate. AWL states that NMFS' 2008 Biological Opinion
does not adequately consider site-specific information related to
Shell's proposed drilling. AWL points out that Shell has proposed
exploration drilling in Camden Bay in the Beaufort Sea, and that Camden
Bay has been repeatedly identified as a resting and feeding area for
migrating bowheads, which has been reaffirmed by the recent monitoring.
AWL states that NMFS should re-examine the potential impacts of Shell's
proposed drilling in light of its long-standing policy and the
cautionary language contained in its 2008 opinion.
Response: NMFS initiated a section 7 consultation under the ESA for
the potential impacts to ESA-listed marine mammal species that could be
adversely affected as a result of several oil and gas related
activities in the 2010 open-water season. The 2010 Biological Opinion
covered the activities by Shell, Statoil, and ION's proposed open water
marine and seismic survey activities. However, as far as Shell's
drilling activities are concerned, Shell has withdrawn these actions
due to the moratorium on offshore drilling.
Comment 38: AWL argues that NMFS' 2008 Biological Opinion does not
adequately consider oil spills. AWL states that in the 2008 Biological
Opinion, NMFS recognized the potential dangers of a large oil spill,
and that whales contacting oil, particularly freshly-spilled oil,
``could be harmed and possibly killed.'' Citing NMFS's finding in its
2008 Biological Opinion that several ``coincidental events'' would have
to take place for such harm to occur: (1) A spill; (2) that coincides
with the whales' seasonal presence; (3) that is ``transported to the
area the whales occupy (e.g., the migrational corridor or spring lead
system)''; and (4) is not successfully cleaned up. AWL points out that
this combination of events is not as remote as NMFS appears to have
assumed because NMFS' analysis of whether a spill may occur relies in
part on statistical probabilities based on past incidents. AWL states
that there appears to have been a significant breakdown in the system
that was intended to both prevent spills from occurring and require
adequate oil spill response capabilities to limit the harm. AWL states
that NMFS must take into account that there are likely gaps in the
current regulatory regime, and that given those flaws, an analysis that
relies on the safety record of previous drilling is doubtful as a
predictive tool.
Response: As discussed in the previous Response to Comment, no
drilling is planned for Shell during the 2010 open water season,
therefore, these activities will be considered in a separate
consultation if and when Shell proposes to conduct exploratory drilling
because seismic activities do not raise an oil-spill concern.
NEPA Concerns
Comment 39: AEWC believes that NMFS, in direct contravention of the
law, excluded the public from the NEPA process since NMFS did not
release a draft EA for the public to review and provide comments prior
to NMFS taking its final action.
Response: Neither NEPA nor the Council on Environmental Quality's
(CEQ) regulations explicitly require circulation of a draft EA for
public comment prior to finalizing the EA. The Federal courts have
upheld this conclusion, and in one recent case, the Ninth Circuit
squarely addressed the question of public involvement in the
development of an EA. In Bering Strait Citizens for Responsible
Resource Development v. U.S. Army Corps of Engineers (524 F.3d 938, 9th
Cir. 2008), the court held that the circulation of a draft EA is not
required in every case; rather, Federal agencies should strive to
involve the public in the decision-making process by providing as much
environmental information as is practicable prior to completion of the
EA so that the public has a sufficient opportunity to weigh in on
issues pertinent to the agency's decision-making process. In the case
of Shell's 2010 MMPA IHA request, NMFS involved the public in the
decision-making process by distributing Shell's IHA application and
addenda for a 30-
[[Page 49729]]
day notice and comment period. However, at that time, a draft EA was
not available to provide to the public for comment. The IHA application
and NMFS' Notice of Proposed IHA (75 FR 27708; May 18, 2010) contained
information relating to the project. For example, the application
included a project description, its location, environmental matters
such as species and habitat to be affected, and measures designed to
minimize adverse impacts to the environment and the availability of
affected species or stocks for subsistence uses.
Comment 40: AEWC notes that Shell's IHA application warrants review
in an environmental impact statement (EIS) given the potential for
significant impacts.
Response: NMFS' 2010 EA was prepared to evaluate whether
significant environmental impacts may result from the issuance of an
IHA to Shell, which is an appropriate application of NEPA. After
completing the EA, NMFS determined that there would not be significant
impacts to the human environment and accordingly issued a FONSI.
Therefore, an EIS is not needed for this action.
Comment 41: AEWC, AWL, and NSB note that NMFS is preparing a
Programmatic EIS (PEIS). Although MMS published a draft PEIS (PEIS; MMS
2007) in the summer of 2007, to date, a Final PEIS has not been
completed. AWL also notes that NMFS and MMS have reaffirmed their
previous determination that a programmatic EIS process is necessary to
address the overall, cumulative impacts of increased oil and gas
activity in the Arctic Ocean and intend to incorporate into that
analysis new scientific information as well as new information about
projected seismic and exploratory drilling activity in both seas.
However, AWL and AEWC argue that NEPA regulations make clear that NMFS
should not proceed with authorizations for individual projects like
Shell's surveying until its programmatic EIS is complete. NSB states
that it would be regretful for Shell to proceed on a one-year IHA when
the impact of those activities could have a catastrophic impact on
Arctic resources and foreclose management options to be developed in
the forthcoming EIS.
Response: While the Final PEIS will analyze the affected
environment and environmental consequences from seismic surveys in the
Arctic, the analysis contained in the Final PEIS will apply more
broadly to Arctic oil and gas operations. NMFS' issuance of an IHA to
Shell for the taking of several species of marine mammals incidental to
conducting its open-water marine survey program in the Chukchi and
Beaufort Seas in 2010, as analyzed in the EA, is not expected to
significantly affect the quality of the human environment. Shell's
surveys are not expected to significantly affect the quality of the
human environment because of the limited duration and scope of Shell's
operations. Additionally, the EA contained a full analysis of
cumulative impacts.
Miscellaneous Issues
Comment 42: The AEWC states that Shell was unable to reach an
accord on the annual CAA with AEWC. AEWC states that the CAA has
historically formed the basis for NMFS' statutorily required
determination of no unmitigable adverse impacts to subsistence
activities. Specifically, AEWC states that Shell was not able to reach
agreement with AEWC on (1) provisions for zero discharge and (2) on the
sound threshold for activities that should be subject to sound source
verification procedures. AEWC requests NMFS to fulfill its
Congressional mandate and ensure that Shell's activities do not have
more than a negligible impact on marine mammal stocks or an unmitigable
adverse impact on the subsistence activities. The Commission also
recommends that NMFS require Shell to engage in consultations with
Alaska Native communities that may be affected by the company's
activities and, to the extent feasible, seek to resolve any Alaska
Native concerns through negotiation of a CAA.
Response: AEWC states that the CAA has historically formed the
basis for NMFS' statutorily required determination of no unmitigable
adverse impacts to subsistence activities, which is incorrect. Under
sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.), an
IHA or LOA shall be granted to U.S. citizens who engage in a specified
activity (other than commercial fishing) within a specified
geographical region if NMFS finds that the taking of marine mammals
will have a negligible impact on the species or stock(s) and will not
have an unmitigable adverse impact on the availability of the species
or stock(s) for certain subsistence uses, and if the permissible
methods of taking and requirements pertaining to the mitigation,
monitoring and reporting of such takings are set forth. In other words,
no marine mammal take authorizations may be issued if NMFS has reason
to believe that the proposed exploration or development activities
would have an unmitigable adverse impact on the availability of marine
mammal species or stock(s) for Alaskan native subsistence uses.
Although Federal laws do not require consultation with the native
coastal communities until after offshore exploration and development
plans have been finalized, permitted, and authorized, pre-permitting
consultations between the oil and gas industry and the Alaskan coastal
native communities are considered by NMFS when the agency makes a
determination whether such activities would have an unmitigable adverse
impact on the availability of marine mammal species or stock(s) for
subsistence uses. For the proposed marine surveys, Shell has conducted
POC meetings for its seismic operations in the Beaufort and Chukchi
Seas in the communities and villages of Nuiqsut, Kaktovik, Barrow,
Kotzebue, Wainwright, Point Lay, and Point Hope.
Shell has not signed the 2010 CAA with Alaska Natives and has
informed NMFS that it does not intend to do so. NMFS has scrutinized
all of the documents submitted by Shell (e.g., IHA application, Plan of
Cooperation and other correspondence to NMFS and affected stakeholders)
and documents submitted by other affected stakeholders and concluded
that harassment of marine mammals incidental to Shell's activities will
not have more than a negligible impact on marine mammal stocks or an
unmitigable adverse impact on the availability of marine mammals for
taking for subsistence uses. This finding was based in large part on
NMFS' definition of ``negligible impact,'' ``unmitigable adverse
impact,'' the proposed mitigation and monitoring measures, the scope of
activities proposed to be conducted, including time of year, location
and presence of marine mammals in the project area, and Shell's Plan of
Cooperation.
As described in Shell's IHA application, the source vessel will
transit through the Chukchi Sea along a route that lies offshore of the
polynya zone. This entry into the Chukchi Sea will not occur before
July 1, 2010. In the event the transit outside of the polynya zone
results in Shell having to move away from ice, the source vessel may
enter into the polynya zone. If it is necessary to move into the
polynya zone, Shell will notify the local communities of the change in
the transit route through the Com Centers.
Shell has developed a Communication Plan and will implement the
plan before initiating the 2010 program to coordinate activities with
local subsistence users as well as Village Whaling Associations in
order to minimize the risk of interfering with
[[Page 49730]]
subsistence hunting activities, and keep current as to the timing and
status of the bowhead whale migration, as well as the timing and status
of other subsistence hunts. The Communication Plan includes procedures
for coordination with Communication and Call Centers to be located in
coastal villages along the Beaufort and Chukchi Seas during Shell's
program in 2010.
Shell will employ local Subsistence Advisors from the Beaufort and
Chukchi Sea villages to provide consultation and guidance regarding the
whale migration and subsistence hunt. There may be up to nine
subsistence advisor-liaison positions (one per village), to work
approximately 8 hours per day and 40-hour weeks through Shell's 2010
program. The subsistence advisor will use local knowledge to gather
data on subsistence lifestyle within the community and advise as to
ways to minimize and mitigate potential impacts to subsistence
resources during program activities. Responsibilities include reporting
any subsistence concerns or conflicts; coordinating with subsistence
users; reporting subsistence-related comments, concerns, and
information; and advising how to avoid subsistence conflicts. A
subsistence advisor handbook will be developed prior to the operational
season to specify position work tasks in more detail.
Shell will also implement flight restrictions prohibiting aircraft
from flying within 1,000 ft (300 m) of marine mammals or below 1,500 ft
(457 m) altitude (except during takeoffs and landings or in emergency
situations) while over land or sea.
Besides bowhead whale hunting, beluga whales are hunted for
subsistence at Barrow, Wainwright, Point Lay, and Point Hope, with the
most taken by Point Lay (Fuller and George 1997). Harvest at all of
these villages generally occurs between April and July with most taken
in April and May when pack-ice conditions deteriorate and leads open
up. Ringed, bearded, and spotted seals are hunted by all of the
villages bordering the project area (Fuller and George 1997). Ringed
and bearded seals are hunted throughout the year, but most are taken in
May, June, and July when ice breaks up and there is open water instead
of the more difficult hunting of seals at holes and lairs. Spotted
seals are only hunted in spring through summer.
Therefore, the scheduling of the proposed marine surveys is
expected to have minimum conflict between the industries and marine
mammal harvests.
Finally, the required mitigation and monitoring measures are
expected to reduce any adverse impacts on marine mammals for taking for
subsistence uses to the extent practicable. These measures include, but
are not limited to, the 180 dB and 190 dB safety (shut-down/power-down)
zones; a requirement to monitor the 160 dB isopleths for aggregations
of 12 or more non-migratory balaenidae whales and when necessary shut
down seismic airguns; reducing vessel speed to 10 knots or less when a
vessel is within 300 yards of whales to avoid a collision; utilizing
communication centers to avoid any conflict with subsistence hunting
activities; and the use of marine mammal observers.
Measures related to ``zero volume discharge'' do not affect NMFS'
negligible determination on impacts of the species or stock(s) or the
unmitigable adverse impact determination on the availability of the
species or stock(s) for certain subsistence uses, as long as Shell's
emission discharge is within the guidelines set by the Environmental
Protection Agency (EPA). Regarding the sound source verification (SSV),
NMFS requires Shell to conduct SSV tests for all its airgun and active
acoustic sources and seismic and support vessels that will be involved
in the proposed marine surveys.
Over the past several months, NMFS has worked with both Alaska
Native communities and the industry, to the extent feasible, to resolve
any Alaska Native concerns from the proposed open water marine and
seismic surveys. These efforts include convening an open water
stakeholders' meeting in Anchorage, AK, in March 2010, and multiple
conference meetings with representatives of the Alaska Native
communities and the industry. Lastly, as mentioned previously in this
document, NMFS has included several measures from the CAA in the IHA
issued to Shell.
Comment 43: AEWC notes that, in 2009, NMFS did not publish its
response to comments on proposed IHAs activities conducted during the
open water season until well after the fall subsistence hunt at Cross
Island had concluded and geophysical operations had already taken
place. AEWC states that NMFS' failure to release its response to
comments until after the activities had taken place casts serious doubt
on the validity of NMFS' public involvement process and the underlying
analysis of impacts to subsistence activities and marine mammals.
Response: NMFS does not agree with AEWC's statement that NMFS'
failure to release its response to comments until after the activities
had taken place casts doubt on the validity of NMFS' public involvement
process, or the underlying analysis of impacts to subsistence
activities and marine mammals. As stated earlier, the decision to issue
an IHA to Shell for its proposed marine surveys in the Beaufort and
Chukchi Seas is based in large part on NMFS' definition of ``negligible
impact,'' ``unmitigable adverse impact,'' the proposed mitigation and
monitoring measures, the scope of activities proposed to be conducted,
including time of year, location and presence of marine mammals in the
project area, extensive research and studies on potential impacts of
anthropogenic sounds to marine mammals, marine mammal behavior,
distribution, and movements in the vicinity of Shell's proposed project
areas, Shell's Plan of Cooperation, and on public comments received
during the commenting period and peer-review recommendations by an
independent review panel. The reason that NMFS was not able to publish
its response to comments on proposed IHA activities in 2009 for Shell's
shallow hazards and site clearance surveys until the end of the survey
activities was due to the large amount of comments NMFS received. NMFS
was able to review and analyze all comments it received and address
their validity for the issuance of the IHA. However, due to the large
volume of comments, NMFS was not able to organize them into publishable
format to be incorporated into the Federal Register notice for
publication on a timely basis. NMFS will strive to make sure that all
comments are addressed in full and published by the time IHAs or LOAs
are issued.
Comment 44: AEWC states that Shell failed to provide plans for
community engagement. AEWC states that Shell is required to include in
its application a ``schedule for meeting with affected subsistence
communities to discuss proposed activities and to resolve potential
conflicts regarding any aspects of either the operation or the plan of
cooperation.'' (50 CFR 216.104(a)(12)(ii)). However, AEWC notes that in
its application, Shell only just mentions that it held a few meetings
and ``anticipates continued engagement.'' AEWC argues that this vague
intention to participate in more meetings with the affected communities
is insufficient and does not satisfy the regulatory requirement. AEWC
points out that Shell is also required to provide its plans for
continuing to meet with communities. AEWC notes that while Shell
mentions communicating with communities via its SA and Com and
[[Page 49731]]
Call Center program, which allows for the availability of back and
forth communication, the company has described no actual, planned
communication with the affected communities.
Response: The information AEWC contained in the comment is
outdated. Since the submission of Shell's IHA application, Shell
indicated that it completed its pre-season Plan of Cooperation meetings
for the 2010 season in early April 2010. Through the Subsistence
Advisor (SA) and Com and Call Center (Com Center) program for 2010,
Shell's SA and Shell representatives in the Com Centers will be
available daily to the communities throughout the 2010 season. The SA
and Com Center programs provide residents of the nearest affected
communities a way to communicate where and when subsistence activities
occur so that industry may avoid conflicts with planned subsistence
activities.
Comment 45: NSB states that NMFS should consider and address
disproportionate impacts in analyzing the IHA application, that Federal
agencies must ``make achieving environmental justice part of * * *
[their] mission[s].'' Compared to many United States residents, NSB
states that Alaskan Natives face significant impacts from oil and gas
activities in the OCS. NSB requests that NMFS thus specifically address
issues of environmental justice in considering this application and
that NMFS must also work to ensure effective public participation and
access to information, and must ``ensure that public documents,
notices, and hearings relating to human health or the environment are
concise, understandable, and readily accessible to the public.''
Response: Under section 101(a)(5)(D) of the MMPA, NMFS is required
to determine whether the taking by the applicant's specified activity
will take only small numbers of marine mammals, will have a negligible
impact on the affected marine mammal species or population stocks, and
will not have an unmitigable impact on the availability of affected
species or stocks for subsistence uses. Environmental justice and other
impacts to the human environment are NMFS' responsibility under the
NEPA and applicable executive orders, not the MMPA. In that regard,
NMFS' 2010 EA addresses the potential cumulative impacts to the
socioeconomic environment, including traditional knowledge, community
and economy of the Alaskan Arctic, subsistence harvesting, and coastal
and marine use issues. Please refer to NMFS' 2010 EA for these
assessments.
In addition, NMFS has been working with the public to ensure public
participation, which includes the public review and comments on Shell's
IHA application and the proposed IHA. All documents related to this
action are available through the NMFS Office of Protected Resources Web
site at http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
Description of Marine Mammals in the Area of the Specified Activity
Nine cetacean and four pinniped species under NMFS jurisdiction
could occur in the general area of Shell's open water marine survey
areas in the Beaufort and Chukchi Seas. The species most likely to
occur in the general area near Harrison Bay in the Alaskan Beaufort Sea
include two cetacean species: Beluga (Delphinapterus leucas) and
bowhead whales (Balaena mysticetus) and three seal species: Ringed
(Phoca hispida), spotted (P. largha), and bearded seals (Erignathus
barbatus). Most encounters are likely to occur in nearshore shelf
habitats or along the ice edge. The marine mammal species that is
likely to be encountered most widely (in space and time) throughout the
period of the planned shallow hazards surveys is the ringed seal.
Encounters with bowhead and beluga whales are expected to be limited to
particular regions and seasons, as discussed below.
Other marine mammal species that have been observed in the Beaufort
and Chukchi Seas but are less frequent or uncommon in the Beaufort Sea
project area include harbor porpoise (Phocoena phocoena), narwhal
(Monodon monoceros), killer whale (Orcinus orca), fin whale
(Balaenoptera physalus), minke whale (B. acutorostrata), humpback whale
(Megaptera novaeangliae), gray whale (Eschrichtius robustus), and
ribbon seal (Histriophoca fasciata). These species could occur in the
project area, but each of these species is uncommon or rare in the area
and relatively few encounters with these species are expected during
the proposed marine surveys. The narwhal occurs in Canadian waters and
occasionally in the Beaufort Sea, but it is rare there and is not
expected to be encountered. There are scattered records of narwhal in
Alaskan waters, including reports by subsistence hunters, where the
species is considered extralimital (Reeves et al. 2002). Point Barrow,
Alaska, is the approximate northeastern extent of the harbor porpoise's
regular range (Suydam and George 1992), though there are extralimital
records east to the mouth of the Mackenzie River in the Northwest
Territories, Canada, and recent sightings in the Beaufort Sea in the
vicinity of Prudhoe Bay during surveys in 2007 and 2008 (Christie et
al. 2009). Monnett and Treacy (2005) did not report any harbor porpoise
sightings during aerial surveys in the Beaufort Sea from 2002 through
2004. Humpback, fin, and minke whales have recently been sighted in the
Chukchi Sea but very rarely in the Beaufort Sea. Greene et al. (2007)
reported and photographed a humpback whale cow/calf pair east of Barrow
near Smith Bay in 2007, which is the first known occurrence of
humpbacks in the Beaufort Sea. Savarese et al. (2009) reported one
minke whale sighting in the Beaufort Sea in 2007 and 2008. Ribbon seals
do not normally occur in the Beaufort Sea; however, two ribbon seal
sightings were reported during vessel-based activities near Prudhoe Bay
in 2008 (Savarese et al. 2009).
The bowhead and humpback whales are listed as ``endangered'' under
the Endangered Species Act (ESA) and as depleted under the MMPA.
Certain stocks or populations of gray, beluga, and killer whales and
spotted seals are listed as endangered or proposed for listing under
the ESA; however, none of those stocks or populations occur in the
proposed activity area. Additionally, the ribbon seal is considered a
``species of concern'' under the ESA, and the bearded and ringed seals
are ``candidate species'' under the ESA, meaning they are currently
being considered for listing.
Shell's application contains information on the status,
distribution, seasonal distribution, and abundance of each of the
species under NMFS jurisdiction mentioned in this document. Please
refer to the application for that information (see ADDRESSES).
Additional information can also be found in the NMFS Stock Assessment
Reports (SAR). The Alaska 2009 SAR is available at: http://www.nmfs.noaa.gov/pr/pdfs/sars/ak2009.pdf.
Monitoring Plan Peer Review
The MMPA requires that monitoring plans be independently peer
reviewed ``where the proposed activity may affect the availability of a
species or stock for taking for subsistence uses'' (16 U.S.C.
1371(a)(5)(D)(ii)(III)). Regarding this requirement, NMFS' implementing
regulations state, ``Upon receipt of a complete monitoring plan, and at
its discretion, [NMFS] will either submit the plan to members of a peer
review panel for review or within 60 days of receipt of the proposed
monitoring plan,
[[Page 49732]]
schedule a workshop to review the plan'' (50 CFR 216.108(d)).
NMFS convened an independent peer review panel to review Shell's
Marine Mammal Monitoring and Mitigation Plan (4MP) for the Open Water
Marine Survey Program in the Beaufort and Chukchi Seas, Alaska, during
2010. The panel met on March 25 and 26, 2010, and provided their final
report to NMFS on April 22, 2010. The full panel report can be viewed
at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
NMFS provided the panel with Shell's 4MP and asked the panel to
address the following questions and issues for Shell's plan:
(1) The monitoring program should document the effects (including
acoustic) on marine mammals and document or estimate the actual level
of take as a result of the activity. Does the monitoring plan meet this
goal?
(2) Ensure that the monitoring activities and methods described in
the plan will enable the applicant to meet the requirements listed in
(1) above;
(3) Are the applicant's objectives achievable based on the methods
described in the plan?
(4) Are the applicant's objectives the most useful for
understanding impacts on marine mammals?
(5) Should the applicant consider additional monitoring methods or
modifications of proposed monitoring methods for the proposed activity?
And
(6) What is the best way for an applicant to report their data and
results to NMFS?
Section 3 of the report contains recommendations that the panel
members felt were applicable to all of the monitoring plans reviewed
this year. Section 4.4 of the report contains recommendations specific
to Shell's Open Water Marine Survey Program 4MP. Specifically, for the
general recommendations, the panel commented on issues related to: (1)
Acoustic effects of oil and gas exploration--assessment and mitigation;
(2) aerial surveys; (3) MMOs; (4) visual near-field monitoring; (5)
visual far-field monitoring; (6) baseline biological and environmental
information; (7) comprehensive ecosystem assessments and cumulative
impacts; (8) duplication of seismic survey effort; and (9) whale
behavior.
NMFS has reviewed the report and evaluated all recommendations made
by the panel. NMFS has determined that there are several measures that
Shell can incorporate into its 2010 Open Water Marine Survey Program
4MP to improve it. Additionally, there are other recommendations that
NMFS has determined would also result in better data collection, and
could potentially be implemented by oil and gas industry applicants,
but which likely could not be implemented for the 2010 open water
season due to technical issues (see below). While it may not be
possible to implement those changes this year, NMFS believes that they
are worthwhile and appropriate suggestions that may require a bit more
time to implement, and Shell should consider incorporating them into
future monitoring plans should Shell decide to apply for IHAs in the
future.
The following subsections lay out measures that NMFS recommends for
implementation as part of the 2010 Open Water Marine Survey Program 4MP
and those that are recommended for future programs.
Recommendations for Inclusion in the 2010 4MP and IHA
Section 3.3 of the panel report contains several recommendations
regarding MMOs, which NMFS agrees that Shell should incorporate:
Observers should be trained using visual aids (e.g.,
videos, photos), to help them identify the species that they are likely
to encounter in the conditions under which the animals will likely be
seen.
Observers should understand the importance of classifying
marine mammals as ``unknown'' or ``unidentified'' if they cannot
identify the animals to species with confidence. In those cases, they
should note any information that might aid in the identification of the
marine mammal sighted. For example, for an unidentified mysticete
whale, the observers should record whether the animal had a dorsal fin.
Observers should attempt to maximize the time spent
looking at the water and guarding the safety radii. They should avoid
the tendency to spend too much time evaluating animal behavior or
entering data on forms, both of which detract from their primary
purpose of monitoring the safety zone.
`Big eye' binoculars (25 x 150) should be used from high
perches on large, stable platforms. They are most useful for monitoring
impact zones that extend beyond the effective line of sight. With two
or three observers on watch, the use of `big eyes' should be paired
with searching by naked eye, the latter allowing visual coverage of
nearby areas to detect marine mammals. When a single observer is on
duty, the observer should follow a regular schedule of shifting between
searching by naked-eye, low-power binoculars, and big-eye binoculars
based on the activity, the environmental conditions, and the marine
mammals of concern.
Observers should use the best possible positions for
observing (e.g., outside and as high on the vessel as possible), taking
into account weather and other working conditions.
Whenever possible, new observers should be paired with
experienced observers to avoid situations where lack of experience
impairs the quality of observations. If there are Alaska Native MMOs,
the MMO training that is conducted prior to the start of the survey
activities should be conducted with both Alaska Native MMOs and
biologist MMOs being trained at the same time in the same room. There
should not be separate training courses for the different MMOs.
In Section 3.4, panelists recommend collecting some additional data
to help verify the utility of the ``ramp-up'' requirement commonly
contained in IHAs. To help evaluate the utility of ramp-up procedures,
NMFS will require observers to record and report their observations
during any ramp-up period. An analysis of these observations may lead
to the conclusion regarding the effectiveness of ramp-up and should be
included in the monitoring report.
Among other things, Section 3.5 of the panel report recommends
recording visibility data because of the concern that the line-of-sight
distance for observing marine mammals is reduced under certain
conditions. MMOs should ``carefully document visibility during
observation periods so that total estimates of take can be corrected
accordingly''.
Section 4.4 of the report contains recommendations specific to
Shell's Open Water Marine Survey Program 4MP. Of the recommendations
presented in this section, NMFS has determined that the following
should be implemented for the 2010 season:
Summarize observation effort and conditions, the number of
animals seen by species, the location and time of each sighting,
position relative to the survey vessel, the company's activity at the
time, each animal's response, and any adjustments made to operating
procedures. Provide all spatial data on charts (always including vessel
location).
Make all data available in the report or (preferably)
electronically for integration with data from other companies.
Accommodate specific requests for raw data, including
tracks of all vessels and aircraft associated with the operation and
activity logs documenting when and what types of sounds are
[[Page 49733]]
introduced into the environment by the operation.
NMFS spoke with Shell about the inclusion of these recommendations
into the 2010 4MP and IHA. Shell indicated to NMFS that they will
incorporate these recommendations into the 4MP, and NMFS has made
several of these recommendations requirements in the IHA.
Recommendations for Inclusion in Future Monitoring Plans
Section 3.5 of the report recommends methods for conducting
comprehensive monitoring of a large-scale seismic operation. One method
for conducting this monitoring recommended by panel members is the use
of passive acoustic devices. Additionally, Section 3.2 of the report
encourages the use of such systems if aerial surveys will not be used
for real-time mitigation monitoring. NMFS acknowledges that there are
challenges involved in using this technology to detect bowhead whale
vocalizations in conjunction with seismic airguns in this environment,
especially in real time. However, NMFS recommends that Shell work to
help develop and improve this type of technology for use in the Arctic
(and use it once it is available and effective), as it could be
valuable both for real-time mitigation implementation, as well as
archival data collection. Shell indicated to NMFS that they have been
working for several years to aid in the development of such technology
and will continue to do so.
The panelists also recommend adding a tagging component to
monitoring plans. ``Tagging of animals expected to be in the area where
the survey is planned also may provide valuable information on the
location of potentially affected animals and their behavioral responses
to industrial activities. Although the panel recognized that such
comprehensive monitoring might be difficult and expensive, such an
effort (or set of efforts) reflects the complex nature of the challenge
of conducting reliable, comprehensive monitoring for seismic or other
relatively-intense industrial operations that ensonify large areas of
ocean.'' While this particular recommendation is not feasible for
implementation in 2010, NMFS recommends that Shell consider adding a
tagging component to future seismic survey monitoring plans should
Shell decide to conduct such activities in future years. Shell
currently helps to fund the U.S. Geological Survey's walrus tagging
project in the Arctic and is open to the idea of helping to fund other
marine mammal tagging projects in the Arctic.
To the extent possible, NMFS recommends implementing the
recommendation contained in Section 4.4.6 for the 2010 season:
``Integrate all observer data with information from tagging and
acoustic studies to provide a more comprehensive description of the
acoustic environment during its survey.'' However, NMFS recognizes that
this integration process may take time to implement. Therefore, Shell
should begin considering methods for the integration of the observer
data now if Shell intends to apply for IHAs in the future.
In Section 3.4, panelists recommend collecting data to evaluate the
efficacy of using forward-looking infrared devices (FLIR) vs. night-
vision binoculars. The panelists note that while both of these devices
may increase detection capabilities by MMOs of marine mammals, the
reliability of these technologies should be tested under appropriate
conditions and their efficacy evaluated. NMFS recommends that Shell
design a study to explore using both FLIR and night-vision binoculars
and collect data on levels of detection of marine mammals using each
type of device.
Other Recommendations in the Report
The panel also made several recommendations, which are not
discussed in the two preceding subsections. NMFS determined that many
of the recommendations were made beyond the bounds of what the panel
members were tasked to do. For example, the panel recommended that NMFS
begin a transition away from using a single metric of acoustic exposure
to estimate the potential effects of anthropogenic sound on marine
living resources. This is not a recommendation about monitoring but
rather addresses a NMFS policy issue. NMFS is currently in the process
of revising its acoustic guidelines on a national scale. A
recommendation was also made regarding the training and oversight of
MMOs. NMFS is currently working on a national policy for this as well
Section 3.7 of the report contains several recommendations regarding
comprehensive ecosystem assessments and cumulative impacts. These are
good, broad recommendations, however, the implementation of these
recommendations would not be the responsibility solely of oil and gas
industry applicants. The recommendations require the cooperation and
input of several groups, including Federal, state, and local government
agencies, members of other industries, and members of the scientific
research community. NMFS will encourage the industry and others to
build the relationships and infrastructure necessary to pursue these
goals, and incorporate these recommendations into future MMPA
authorizations, as appropriate. Lastly, Section 3.8 of the report makes
a recommendation regarding data sharing and reducing the duplication of
seismic survey effort. While this is a valid recommendation, it does
not relate to monitoring or address any of the six questions with which
the panel members were tasked to answer.
For some of the recommendations, NMFS felt that additional
clarification was required by the panel members before NMFS could
determine whether or not applicants should incorporate them into the
monitoring plans. Section 3.2 of the report discusses the use of and
methods for conducting aerial surveys. Industry applicants have not
conducted aerial surveys in Chukchi Sea lease sale areas for several
years because of the increased risk for flying there (as noted by the
panel report). To that end, NMFS has asked the panel to provide
recommendations on whether or not similar surveys could be conducted
from dedicated vessel-based platforms. NMFS also asked for additional
clarification on some of the recommendations regarding data collection
and take estimate calculations. In addition, NMFS asked the panel
members for clarification on the recommendation contained in Section
3.6 regarding baseline studies. Lastly, NMFS asked the panel members
for clarification on the recommendation specific to Shell contained in
Section 4.4 regarding estimating statistical power for all methods
intended to detect adverse impacts. Once NMFS hears back from the panel
and is clear with these recommendations, NMFS will follow up with Shell
and discuss the implementation of these additional measures in future
years.
Potential Effects of the Specified Activity on Marine Mammals
Operating a variety of active acoustic sources such as airguns,
side-scan sonars, echo-sounders, and sub-bottom profilers for site
clearance and shallow hazard surveys, ice gouge, and strudel surveys
can impact marine mammals in a variety of ways.
Potential Effects of Airgun and Sonar Sounds on Marine Mammals
The effects of sounds from airgun pulses might include one or more
of the following: tolerance, masking of natural sounds, behavioral
disturbance, and
[[Page 49734]]
temporary or permanent hearing impairment or non-auditory effects
(Richardson et al. 1995). As outlined in previous NMFS documents, the
effects of noise on marine mammals are highly variable, and can be
categorized as follows (based on Richardson et al. 1995):
(1) Tolerance
Numerous studies have shown that pulsed sounds from airguns are
often readily detectable in the water at distances of many kilometers.
Numerous studies have also shown that marine mammals at distances more
than a few kilometers from operating seismic vessels often show no
apparent response. That is often true even in cases when the pulsed
sounds must be readily audible to the animals based on measured
received levels and the hearing sensitivity of that mammal group.
Although various baleen whales, toothed whales, and (less frequently)
pinnipeds have been shown to react behaviorally to airgun pulses under
some conditions, at other times, mammals of all three types have shown
no overt reactions. In general, pinnipeds and small odontocetes seem to
be more tolerant of exposure to airgun pulses than baleen whales.
(2) Behavioral Disturbance
Marine mammals may behaviorally react to sound when exposed to
anthropogenic noise. These behavioral reactions are often shown as:
changing durations of surfacing and dives, number of blows per
surfacing, or moving direction and/or speed; reduced/increased vocal
activities; changing/cessation of certain behavioral activities (such
as socializing or feeding); visible startle response or aggressive
behavior (such as tail/fluke slapping or jaw clapping); avoidance of
areas where noise sources are located; and/or flight responses (e.g.,
pinnipeds flushing into water from haulouts or rookeries).
The biological significance of many of these behavioral
disturbances is difficult to predict, especially if the detected
disturbances appear minor. However, the consequences of behavioral
modification could be expected to be biologically significant if the
change affects growth, survival, and reproduction. Some of these
significant behavioral modifications include:
Drastic change in diving/surfacing patterns (such as those
thought to be causing beaked whale stranding due to exposure to
military mid-frequency tactical sonar);
Habitat abandonment due to loss of desirable acoustic
environment; and
Cease feeding or social interaction.
For example, at the Guerreo Negro Lagoon in Baja California,
Mexico, which is one of the important breeding grounds for Pacific gray
whales, shipping and dredging associated with a salt works may have
induced gray whales to abandon the area through most of the 1960s
(Bryant et al. 1984). After these activities stopped, the lagoon was
reoccupied, first by single whales and later by cow-calf pairs.
The onset of behavioral disturbance from anthropogenic noise
depends on both external factors (characteristics of noise sources and
their paths) and the receiving animals (hearing, motivation,
experience, demography) and is also difficult to predict (Southall et
al. 2007).
Currently NMFS uses 160 dB re 1 [mu]Pa at received level for
impulse noises (such as airgun pulses) as the onset of marine mammal
behavioral harassment.
Mysticete: Baleen whales generally tend to avoid operating airguns,
but avoidance radii are quite variable. Whales are often reported to
show no overt reactions to airgun pulses at distances beyond a few
kilometers, even though the airgun pulses remain well above ambient
noise levels out to much longer distances (reviewed in Richardson et
al. 1995; Gordon et al. 2004). However, studies done since the late
1990s of migrating humpback and migrating bowhead whales show
reactions, including avoidance, that sometimes extend to greater
distances than documented earlier. Avoidance distances often exceed the
distances at which boat-based observers can see whales, so observations
from the source vessel can be biased. Observations over broader areas
may be needed to determine the range of potential effects of some
large-source seismic surveys where effects on cetaceans may extend to
considerable distances (Richardson et al. 1999; Moore and Angliss
2006). Longer-range observations, when required, can sometimes be
obtained via systematic aerial surveys or aircraft-based observations
of behavior (e.g., Richardson et al. 1986, 1999; Miller et al. 1999,
2005; Yazvenko et al. 2007a, 2007b) or by use of observers on one or
more support vessels operating in coordination with the seismic vessel
(e.g., Smultea et al. 2004; Johnson et al. 2007). However, the presence
of other vessels near the source vessel can, at least at times, reduce
sightability of cetaceans from the source vessel (Beland et al. 2009),
thus complicating interpretation of sighting data.
Some baleen whales show considerable tolerance of seismic pulses.
However, when the pulses are strong enough, avoidance or other
behavioral changes become evident. Because the responses become less
obvious with diminishing received sound level, it has been difficult to
determine the maximum distance (or minimum received sound level) at
which reactions to seismic become evident and, hence, how many whales
are affected.
Studies of gray, bowhead, and humpback whales have determined that
received levels of pulses in the 160-170 dB re 1 [mu]Pa (rms) range
seem to cause obvious avoidance behavior in a substantial fraction of
the animals exposed (see review in Southall et al. 2007). In many
areas, seismic pulses diminish to these levels at distances ranging
from 4-15 km from the source. A substantial proportion of the baleen
whales within such distances may show avoidance or other strong
disturbance reactions to the operating airgun array. However, in other
situations, various mysticetes tolerate exposure to full-scale airgun
arrays operating at even closer distances, with only localized
avoidance and minor changes in activities. At the other extreme, in
migrating bowhead whales, avoidance often extends to considerably
larger distances (20-30 km) and lower received sound levels (120-130 dB
re 1 [mu]Pa (rms)). Also, even in cases where there is no conspicuous
avoidance or change in activity upon exposure to sound pulses from
distant seismic operations, there are sometimes subtle changes in
behavior (e.g., surfacing-respiration-dive cycles) that are only
evident through detailed statistical analysis (e.g., Richardson et al.
1986; Gailey et al. 2007).
Data on short-term reactions by cetaceans to impulsive noises are
not necessarily indicative of long-term or biologically significant
effects. It is not known whether impulsive sounds affect reproductive
rate or distribution and habitat use in subsequent days or years.
However, gray whales have continued to migrate annually along the west
coast of North America despite intermittent seismic exploration (and
much ship traffic) in that area for decades (Appendix A in Malme et al.
1984; Richardson et al. 1995), and there has been a substantial
increase in the population over recent decades (Allen and Angliss
2010). The western Pacific gray whale population did not seem affected
by a seismic survey in its feeding ground during a prior year (Johnson
et al. 2007). Similarly, bowhead whales have continued to travel to the
eastern Beaufort Sea each summer despite seismic exploration in their
summer and autumn range for many years (Richardson et al. 1987), and
their numbers have increased
[[Page 49735]]
notably (Allen and Angliss 2010). Bowheads also have been observed over
periods of days or weeks in areas ensonified repeatedly by seismic
pulses (Richardson et al. 1987; Harris et al. 2007). However, it is
generally not known whether the same individual bowheads were involved
in these repeated observations (within and between years) in strongly
ensonified areas. In any event, in the absence of some unusual
circumstances, the history of coexistence between seismic surveys and
baleen whales suggests that brief exposures to sound pulses from any
single seismic survey are unlikely to result in prolonged effects.
Odontocete: Little systematic information is available about
reactions of toothed whales to airgun pulses. Few studies similar to
the more extensive baleen whale/seismic pulse work summarized above
have been reported for toothed whales. However, there are recent
systematic data on sperm whales (e.g., Gordon et al. 2006; Madsen et
al. 2006; Winsor and Mate 2006; Jochens et al. 2008; Miller et al.
2009). There is also an increasing amount of information about
responses of various odontocetes to seismic surveys based on monitoring
studies (e.g., Stone 2003; Smultea et al. 2004; Moulton and Miller
2005; Bain and Williams 2006; Holst et al. 2006; Stone and Tasker 2006;
Potter et al. 2007; Hauser et al. 2008; Holst and Smultea 2008; Weir
2008; Barkaszi et al. 2009; Richardson et al. 2009).
Dolphins and porpoises are often seen by observers on active
seismic vessels, occasionally at close distances (e.g., bow riding).
However, some studies near the U.K., Newfoundland and Angola, in the
Gulf of Mexico, and off Central America have shown localized avoidance.
Also, belugas summering in the Canadian Beaufort Sea showed larger-
scale avoidance, tending to avoid waters out to 10-20 km from operating
seismic vessels. In contrast, recent studies show little evidence of
conspicuous reactions by sperm whales to airgun pulses, contrary to
earlier indications.
There are almost no specific data on responses of beaked whales to
seismic surveys, but it is likely that most if not all species show
strong avoidance. There is increasing evidence that some beaked whales
may strand after exposure to strong noise from tactical military mid-
frequency sonars. Whether they ever do so in response to seismic survey
noise is unknown. Northern bottlenose whales seem to continue to call
when exposed to pulses from distant seismic vessels.
For delphinids, and possibly the Dall's porpoise, the available
data suggest that a >=170 dB re 1 [mu]Pa (rms) disturbance criterion
(rather than >=160 dB) would be appropriate. With a medium-to-large
airgun array, received levels typically diminish to 170 dB within 1-4
km, whereas levels typically remain above 160 dB out to 4-15 km (e.g.,
Tolstoy et al. 2009). Reaction distances for delphinids are more
consistent with the typical 170 dB re 1 [mu]Parms distances.
Due to their relatively higher frequency hearing ranges when
compared to mysticetes, odontocetes may have stronger responses to mid-
and high-frequency sources such as sub-bottom profilers, side scan
sonar, and echo sounders than mysticetes (Richardson et al. 1995;
Southall et al. 2007). Although the mid- and high-frequency active
acoustic sources with operating frequency between 2 and 50 kHz planned
to be used by Shell have much lower power outputs (167-200 dB re 1
[mu]Pa @ 1 m at source level) than those from the airguns, they could
cause mild behavior reactions to odontocete whales because their
operating frequencies fall within the sensitive hearing range of these
animals. However, scientific information is lacking on specific
behavioral responses by odontocetes to mid- and high-frequency sources.
Nevertheless, based on our current knowledge on mysticete reaction
towards low-frequency airgun pulses, we could induce that more or less
similar reactions could be exhibited by odontocete whales towards mid-
and high-frequency sources.
Pinnipeds: Few studies of the reactions of pinnipeds to noise from
open-water seismic exploration have been published (for review of the
early literature, see Richardson et al. 1995). However, pinnipeds have
been observed during a number of seismic monitoring studies. Monitoring
in the Beaufort Sea during 1996-2002 provided a substantial amount of
information on avoidance responses (or lack thereof) and associated
behavior. Additional monitoring of that type has been done in the
Beaufort and Chukchi Seas in 2006-2009. Pinnipeds exposed to seismic
surveys have also been observed during seismic surveys along the U.S.
west coast. Some limited data are available on physiological responses
of pinnipeds exposed to seismic sound, as studied with the aid of radio
telemetry. Also, there are data on the reactions of pinnipeds to
various other related types of impulsive sounds.
Early observations provided considerable evidence that pinnipeds
are often quite tolerant of strong pulsed sounds. During seismic
exploration off Nova Scotia, gray seals exposed to noise from airguns
and linear explosive charges reportedly did not react strongly (J.
Parsons in Greene et al. 1985). An airgun caused an initial startle
reaction among South African fur seals but was ineffective in scaring
them away from fishing gear. Pinnipeds in both water and air sometimes
tolerate strong noise pulses from non-explosive and explosive scaring
devices, especially if attracted to the area for feeding or
reproduction (Mate and Harvey 1987; Reeves et al. 1996). Thus,
pinnipeds are expected to be rather tolerant of, or to habituate to,
repeated underwater sounds from distant seismic sources, at least when
the animals are strongly attracted to the area.
In summary, visual monitoring from seismic vessels has shown only
slight (if any) avoidance of airguns by pinnipeds, and only slight (if
any) changes in behavior. These studies show that many pinnipeds do not
avoid the area within a few hundred meters of an operating airgun
array. However, based on the studies with large sample size, or
observations from a separate monitoring vessel, or radio telemetry, it
is apparent that some phocid seals do show localized avoidance of
operating airguns. The limited nature of this tendency for avoidance is
a concern. It suggests that one cannot rely on pinnipeds to move away,
or to move very far away, before received levels of sound from an
approaching seismic survey vessel approach those that may cause hearing
impairment.
(3) Masking
Chronic exposure to excessive, though not high-intensity, noise
could cause masking at particular frequencies for marine mammals that
utilize sound for vital biological functions. Masking can interfere
with detection of acoustic signals such as communication calls,
echolocation sounds, and environmental sounds important to marine
mammals. Since marine mammals depend on acoustic cues for vital
biological functions, such as orientation, communication, finding prey,
and avoiding predators, marine mammals that experience severe acoustic
masking will have reduced fitness in survival and reproduction.
Masking occurs when noise and signals (that animal utilizes)
overlap at both spectral and temporal scales. For the airgun noise
generated from the proposed marine seismic survey, these are low
frequency (under 1 kHz) pulses with extremely short durations (in the
scale of milliseconds). Lower frequency man-made noises are more likely
to affect detection of communication calls and other potentially
important natural sounds such as surf and prey noise.
[[Page 49736]]
There is little concern regarding masking due to the brief duration of
these pulses and relatively longer silence between airgun shots (9-12
seconds) near the noise source, however, at long distances (over tens
of kilometers away) in deep water, due to multipath propagation and
reverberation, the durations of airgun pulses can be ``stretched'' to
seconds with long decays (Madsen et al. 2006; Clark and Gagnon 2006).
Therefore it could affect communication signals used by low frequency
mysticetes when they occur near the noise band and thus reduce the
communication space of animals (e.g., Clark et al. 2009a, 2009b) and
cause increased stress levels (e.g., Foote et al. 2004; Holt et al.
2009). Further, in areas of shallow water, multipath propagation of
airgun pulses could be more profound, thus affecting communication
signals from marine mammals even at close distances. Nevertheless, the
intensity of the noise is also greatly reduced at such long distances.
Although masking effects of pulsed sounds on marine mammal calls
and other natural sounds are expected to be limited, there are few
specific studies on this. Some whales continue calling in the presence
of seismic pulses and whale calls often can be heard between the
seismic pulses (e.g., Richardson et al. 1986; McDonald et al. 1995;
Greene et al. 1999a, 1999b; Nieukirk et al. 2004; Smultea et al. 2004;
Holst et al. 2005a, 2005b, 2006; Dunn and Hernandez 2009). However,
there is one recent summary report indicating that calling fin whales
distributed in one part of the North Atlantic went silent for an
extended period starting soon after the onset of a seismic survey in
the area (Clark and Gagnon 2006). It is not clear from that preliminary
paper whether the whales ceased calling because of masking, or whether
this was a behavioral response not directly involving masking. Also,
bowhead whales in the Beaufort Sea may decrease their call rates in
response to seismic operations, although movement out of the area might
also have contributed to the lower call detection rate (Blackwell et
al. 2009a; 2009b).
Among the odontocetes, there has been one report that sperm whales
ceased calling when exposed to pulses from a very distant seismic ship
(Bowles et al. 1994). However, more recent studies of sperm whales
found that they continued calling in the presence of seismic pulses
(Madsen et al. 2002; Tyack et al. 2003; Smultea et al. 2004; Holst et
al. 2006; Jochens et al. 2008). Madsen et al. (2006) noted that airgun
sounds would not be expected to mask sperm whale calls given the
intermittent nature of airgun pulses. Dolphins and porpoises are also
commonly heard calling while airguns are operating (Gordon et al. 2004;
Smultea et al. 2004; Holst et al. 2005a, 2005b; Potter et al. 2007).
Masking effects of seismic pulses are expected to be negligible in the
case of the smaller odontocetes, given the intermittent nature of
seismic pulses plus the fact that sounds important to them are
predominantly at much higher frequencies than are the dominant
components of airgun sounds.
Pinnipeds have best hearing sensitivity and/or produce most of
their sounds at frequencies higher than the dominant components of
airgun sound, but there is some overlap in the frequencies of the
airgun pulses and the calls. However, the intermittent nature of airgun
pulses presumably reduces the potential for masking.
Marine mammals are thought to be able to compensate for masking by
adjusting their acoustic behavior such as shifting call frequencies,
increasing call volume and vocalization rates. For example, blue whales
are found to increase call rates when exposed to seismic survey noise
in the St. Lawrence Estuary (Di Iorio and Clark 2009). The North
Atlantic right whales (Eubalaena glacialis) exposed to high shipping
noise increase call frequency (Parks et al. 2007), while some humpback
whales respond to low-frequency active sonar playbacks by increasing
song length (Miller et al. 2000).
(4) Hearing Impairment
Marine mammals exposed to high intensity sound repeatedly or for
prolonged periods can experience hearing threshold shift (TS), which is
the loss of hearing sensitivity at certain frequency ranges (Kastak et
al. 1999; Schlundt et al. 2000; Finneran et al. 2002; 2005). TS can be
permanent (PTS), in which case the loss of hearing sensitivity is
unrecoverable, or temporary (TTS), in which case the animal's hearing
threshold will recover over time (Southall et al. 2007). Just like
masking, marine mammals that suffer from PTS or TTS will have reduced
fitness in survival and reproduction, either permanently or
temporarily. Repeated noise exposure that leads to TTS could cause PTS.
For transient sounds, the sound level necessary to cause TTS is
inversely related to the duration of the sound.
TTS: TTS is the mildest form of hearing impairment that can occur
during exposure to a strong sound (Kryter 1985). While experiencing
TTS, the hearing threshold rises and a sound must be stronger in order
to be heard. It is a temporary phenomenon, and (especially when mild)
is not considered to represent physical damage or ``injury'' (Southall
et al. 2007). Rather, the onset of TTS is an indicator that, if the
animal is exposed to higher levels of that sound, physical damage is
ultimately a possibility.
The magnitude of TTS depends on the level and duration of noise
exposure, and to some degree on frequency, among other considerations
(Kryter 1985; Richardson et al. 1995; Southall et al. 2007). For sound
exposures at or somewhat above the TTS threshold, hearing sensitivity
recovers rapidly after exposure to the noise ends. In terrestrial
mammals, TTS can last from minutes or hours to (in cases of strong TTS)
days. Only a few data have been obtained on sound levels and durations
necessary to elicit mild TTS in marine mammals (none in mysticetes),
and none of the published data concern TTS elicited by exposure to
multiple pulses of sound during operational seismic surveys (Southall
et al. 2007).
For toothed whales, experiments on a bottlenose dolphin (Tursiops
truncates) and beluga whale showed that exposure to a single watergun
impulse at a received level of 207 kPa (or 30 psi) peak-to-peak (p-p),
which is equivalent to 228 dB re 1 [mu]Pa (p-p), resulted in a 7 and 6
dB TTS in the beluga whale at 0.4 and 30 kHz, respectively. Thresholds
returned to within 2 dB of the pre-exposure level within 4 minutes of
the exposure (Finneran et al. 2002). No TTS was observed in the
bottlenose dolphin.
Finneran et al. (2005) further examined the effects of tone
duration on TTS in bottlenose dolphins. Bottlenose dolphins were
exposed to 3 kHz tones (non-impulsive) for periods of 1, 2, 4 or 8
seconds (s), with hearing tested at 4.5 kHz. For 1-s exposures, TTS
occurred with SELs of 197 dB, and for exposures >1 s, SEL >195 dB
resulted in TTS (SEL is equivalent to energy flux, in dB re 1
[mu]Pa\2\-s). At an SEL of 195 dB, the mean TTS (4 min after exposure)
was 2.8 dB. Finneran et al. (2005) suggested that an SEL of 195 dB is
the likely threshold for the onset of TTS in dolphins and belugas
exposed to tones of durations 1-8 s (i.e., TTS onset occurs at a near-
constant SEL, independent of exposure duration). That implies that, at
least for non-impulsive tones, a doubling of exposure time results in a
3 dB lower TTS threshold.
However, the assumption that, in marine mammals, the occurrence and
magnitude of TTS is a function of cumulative acoustic energy (SEL) is
probably an oversimplification. Kastak et al. (2005) reported
preliminary
[[Page 49737]]
evidence from pinnipeds that, for prolonged non-impulse noise, higher
SELs were required to elicit a given TTS if exposure duration was short
than if it was longer, i.e., the results were not fully consistent with
an equal-energy model to predict TTS onset. Mooney et al. (2009a)
showed this in a bottlenose dolphin exposed to octave-band non-impulse
noise ranging from 4 to 8 kHz at SPLs of 130 to 178 dB re 1 [mu]Pa for
periods of 1.88 to 30 minutes (min). Higher SELs were required to
induce a given TTS if exposure duration was short than if it was
longer. Exposure of the aforementioned bottlenose dolphin to a sequence
of brief sonar signals showed that, with those brief (but non-impulse)
sounds, the received energy (SEL) necessary to elicit TTS was higher
than was the case with exposure to the more prolonged octave-band noise
(Mooney et al. 2009b). Those authors concluded that, when using (non-
impulse) acoustic signals of duration ~0.5 s, SEL must be at least 210-
214 dB re 1 [mu]Pa2-s to induce TTS in the bottlenose dolphin. The most
recent studies conducted by Finneran et al. also support the notion
that exposure duration has a more significant influence compared to SPL
as the duration increases, and that TTS growth data are better
represented as functions of SPL and duration rather than SEL alone
(Finneran et al. 2010a, 2010b). In addition, Finneran et al. (2010b)
conclude that when animals are exposed to intermittent noises, there is
recovery of hearing during the quiet intervals between exposures
through the accumulation of TTS across multiple exposures. Such
findings suggest that when exposed to multiple seismic pulses, partial
hearing recovery also occurs during the seismic pulse intervals.
For baleen whales, there are no data, direct or indirect, on levels
or properties of sound that are required to induce TTS. The frequencies
to which baleen whales are most sensitive are lower than those to which
odontocetes are most sensitive, and natural ambient noise levels at
those low frequencies tend to be higher (Urick 1983). As a result,
auditory thresholds of baleen whales within their frequency band of
best hearing are believed to be higher (less sensitive) than are those
of odontocetes at their best frequencies (Clark and Ellison 2004). From
this, it is suspected that received levels causing TTS onset may also
be higher in baleen whales. However, no cases of TTS are expected given
the small size of the airguns proposed to be used and the strong
likelihood that baleen whales (especially migrating bowheads) would
avoid the approaching airguns (or vessel) before being exposed to
levels high enough for there to be any possibility of TTS.
In pinnipeds, TTS thresholds associated with exposure to brief
pulses (single or multiple) of underwater sound have not been measured.
Initial evidence from prolonged exposures suggested that some pinnipeds
may incur TTS at somewhat lower received levels than do small
odontocetes exposed for similar durations (Kastak et al. 1999; 2005).
However, more recent indications are that TTS onset in the most
sensitive pinniped species studied (harbor seal, which is closely
related to the ringed seal) may occur at a similar SEL as in
odontocetes (Kastak et al. 2004).
Most cetaceans show some degree of avoidance of seismic vessels
operating an airgun array (see above). It is unlikely that these
cetaceans would be exposed to airgun pulses at a sufficiently high
level for a sufficiently long period to cause more than mild TTS, given
the relative movement of the vessel and the marine mammal. TTS would be
more likely in any odontocetes that bow- or wake-ride or otherwise
linger near the airguns. However, while bow- or wake-riding,
odontocetes would be at the surface and thus not exposed to strong
sound pulses given the pressure release and Lloyd Mirror effects at the
surface. But if bow- or wake-riding animals were to dive intermittently
near airguns, they would be exposed to strong sound pulses, possibly
repeatedly.
If some cetaceans did incur mild or moderate TTS through exposure
to airgun sounds in this manner, this would very likely be a temporary
and reversible phenomenon. However, even a temporary reduction in
hearing sensitivity could be deleterious in the event that, during that
period of reduced sensitivity, a marine mammal needed its full hearing
sensitivity to detect approaching predators, or for some other reason.
Some pinnipeds show avoidance reactions to airguns, but their
avoidance reactions are generally not as strong or consistent as those
of cetaceans. Pinnipeds occasionally seem to be attracted to operating
seismic vessels. There are no specific data on TTS thresholds of
pinnipeds exposed to single or multiple low-frequency pulses. However,
given the indirect indications of a lower TTS threshold for the harbor
seal than for odontocetes exposed to impulse sound (see above), it is
possible that some pinnipeds close to a large airgun array could incur
TTS.
Current NMFS' noise exposure standards require that cetaceans and
pinnipeds should not be exposed to pulsed underwater noise at received
levels exceeding, respectively, 180 and 190 dB re 1 [micro]Pa (rms).
These criteria were taken from recommendations by an expert panel of
the High Energy Seismic Survey (HESS) Team that performed an assessment
on noise impacts by seismic airguns to marine mammals in 1997, although
the HESS Team recommended a 180-dB limit for pinnipeds in California
(HESS 1999). The 180 and 190 dB re 1 [mu]Pa (rms) levels have not been
considered to be the levels above which TTS might occur. Rather, they
were the received levels above which, in the view of a panel of
bioacoustics specialists convened by NMFS before TTS measurements for
marine mammals started to become available, one could not be certain
that there would be no injurious effects, auditory or otherwise, to
marine mammals. As summarized above, data that are now available imply
that TTS is unlikely to occur in various odontocetes (and probably
mysticetes as well) unless they are exposed to a sequence of several
airgun pulses stronger than 190 dB re 1 [mu]Pa (rms). On the other
hand, for the harbor seal, harbor porpoise, and perhaps some other
species, TTS may occur upon exposure to one or more airgun pulses whose
received level equals the NMFS ``do not exceed'' value of 190 dB re 1
[mu]Pa (rms). That criterion corresponds to a single-pulse SEL of 175-
180 dB re 1 [mu]Pa\2\-s in typical conditions, whereas TTS is suspected
to be possible in harbor seals and harbor porpoises with a cumulative
SEL of ~171 and ~164 dB re 1 [mu]Pa\2\-s, respectively.
It has been shown that most large whales and many smaller
odontocetes (especially the harbor porpoise) show at least localized
avoidance of ships and/or seismic operations. Even when avoidance is
limited to the area within a few hundred meters of an airgun array,
that should usually be sufficient to avoid TTS based on what is
currently known about thresholds for TTS onset in cetaceans. In
addition, ramping up airgun arrays, which is standard operational
protocol for many seismic operators, should allow cetaceans near the
airguns at the time of startup (if the sounds are aversive) to move
away from the seismic source and to avoid being exposed to the full
acoustic output of the airgun array. Thus, most baleen whales likely
will not be exposed to high levels of airgun sounds provided the ramp-
up procedure is applied. Likewise, many odontocetes close to the
[[Page 49738]]
trackline are likely to move away before the sounds from an approaching
seismic vessel become sufficiently strong for there to be any potential
for TTS or other hearing impairment. Hence, there is little potential
for baleen whales or odontocetes that show avoidance of ships or
airguns to be close enough to an airgun array to experience TTS.
Therefore, it is not likely that marine mammals in the vicinity of the
proposed open water marine and seismic surveys by Shell and Statoil
would experience TTS as a result of these activities.
PTS: When PTS occurs, there is physical damage to the sound
receptors in the ear. In some cases, there can be total or partial
deafness, whereas in other cases, the animal has an impaired ability to
hear sounds in specific frequency ranges (Kryter 1985). Physical damage
to a mammal's hearing apparatus can occur if it is exposed to sound
impulses that have very high peak pressures, especially if they have
very short rise times. (Rise time is the interval required for sound
pressure to increase from the baseline pressure to peak pressure.)
There is no specific evidence that exposure to pulses of airgun
sound can cause PTS in any marine mammal, even with large arrays of
airguns. However, given the likelihood that some mammals close to an
airgun array might incur at least mild TTS (see above), there has been
further speculation about the possibility that some individuals
occurring very close to airguns might incur PTS (e.g., Richardson et
al. 1995; Gedamke et al. 2008). Single or occasional occurrences of
mild TTS are not indicative of permanent auditory damage, but repeated
or (in some cases) single exposures to a level well above that causing
TTS onset might elicit PTS.
Relationships between TTS and PTS thresholds have not been studied
in marine mammals, but are assumed to be similar to those in humans and
other terrestrial mammals (Southall et al. 2007). Based on data from
terrestrial mammals, a precautionary assumption is that the PTS
threshold for impulse sounds (such as airgun pulses as received close
to the source) is at least 6 dB higher than the TTS threshold on a
peak-pressure basis, and probably >6 dB higher (Southall et al. 2007).
The low-to-moderate levels of TTS that have been induced in captive
odontocetes and pinnipeds during controlled studies of TTS have been
confirmed to be temporary, with no measurable residual PTS (Kastak et
al. 1999; Schlundt et al. 2000; Finneran et al. 2002; 2005; Nachtigall
et al. 2003; 2004). However, very prolonged exposure to sound strong
enough to elicit TTS, or shorter-term exposure to sound levels well
above the TTS threshold, can cause PTS, at least in terrestrial mammals
(Kryter 1985). In terrestrial mammals, the received sound level from a
single non-impulsive sound exposure must be far above the TTS threshold
for any risk of permanent hearing damage (Kryter 1994; Richardson et
al. 1995; Southall et al. 2007). However, there is special concern
about strong sounds whose pulses have very rapid rise times. In
terrestrial mammals, there are situations when pulses with rapid rise
times (e.g., from explosions) can result in PTS even though their peak
levels are only a few dB higher than the level causing slight TTS. The
rise time of airgun pulses is fast, but not as fast as that of an
explosion.
Some factors that contribute to onset of PTS, at least in
terrestrial mammals, are as follows:
Exposure to single very intense sound,
Fast rise time from baseline to peak pressure,
Repetitive exposure to intense sounds that individually
cause TTS but not PTS, and
Recurrent ear infections or (in captive animals) exposure
to certain drugs.
Cavanagh (2000) reviewed the thresholds used to define TTS and PTS.
Based on this review and SACLANT (1998), it is reasonable to assume
that PTS might occur at a received sound level 20 dB or more above that
inducing mild TTS. However, for PTS to occur at a received level only
20 dB above the TTS threshold, the animal probably would have to be
exposed to a strong sound for an extended period, or to a strong sound
with rather rapid rise time.
More recently, Southall et al. (2007) estimated that received
levels would need to exceed the TTS threshold by at least 15 dB, on an
SEL basis, for there to be risk of PTS. Thus, for cetaceans exposed to
a sequence of sound pulses, they estimate that the PTS threshold might
be an M-weighted SEL (for the sequence of received pulses) of ~198 dB
re 1 [mu]Pa\2\-s. Additional assumptions had to be made to derive a
corresponding estimate for pinnipeds, as the only available data on
TTS-thresholds in pinnipeds pertained to nonimpulse sound (see above).
Southall et al. (2007) estimated that the PTS threshold could be a
cumulative SEL of ~186 dB re 1 [mu]Pa\2\-s in the case of a harbor seal
exposed to impulse sound. The PTS threshold for the California sea lion
and northern elephant seal would probably be higher given the higher
TTS thresholds in those species. Southall et al. (2007) also note that,
regardless of the SEL, there is concern about the possibility of PTS if
a cetacean or pinniped received one or more pulses with peak pressure
exceeding 230 or 218 dB re 1 [mu]Pa, respectively. Thus, PTS might be
expected upon exposure of cetaceans to either SEL >=198 dB re 1
[mu]Pa2-s or peak pressure >=230 dB re 1 [mu]Pa. Corresponding proposed
dual criteria for pinnipeds (at least harbor seals) are >=186 dB SEL
and >= 218 dB peak pressure (Southall et al. 2007). These estimates are
all first approximations, given the limited underlying data,
assumptions, species differences, and evidence that the ``equal
energy'' model may not be entirely correct.
Sound impulse duration, peak amplitude, rise time, number of
pulses, and inter-pulse interval are the main factors thought to
determine the onset and extent of PTS. Ketten (1994) has noted that the
criteria for differentiating the sound pressure levels that result in
PTS (or TTS) are location and species specific. PTS effects may also be
influenced strongly by the health of the receiver's ear.
As described above for TTS, in estimating the amount of sound
energy required to elicit the onset of TTS (and PTS), it is assumed
that the auditory effect of a given cumulative SEL from a series of
pulses is the same as if that amount of sound energy were received as a
single strong sound. There are no data from marine mammals concerning
the occurrence or magnitude of a potential partial recovery effect
between pulses. In deriving the estimates of PTS (and TTS) thresholds
quoted here, Southall et al. (2007) made the precautionary assumption
that no recovery would occur between pulses.
It is unlikely that an odontocete would remain close enough to a
large airgun array for sufficiently long to incur PTS. There is some
concern about bowriding odontocetes, but for animals at or near the
surface, auditory effects are reduced by Lloyd's mirror and surface
release effects. The presence of the vessel between the airgun array
and bow-riding odontocetes could also, in some but probably not all
cases, reduce the levels received by bow-riding animals (e.g., Gabriele
and Kipple 2009). The TTS (and thus PTS) thresholds of baleen whales
are unknown but, as an interim measure, assumed to be no lower than
those of odontocetes. Also, baleen whales generally avoid the immediate
area around operating seismic vessels, so it is unlikely that a baleen
whale could incur PTS from exposure to airgun pulses. The TTS (and thus
PTS) thresholds of some pinnipeds (e.g., harbor seal) as well as the
harbor
[[Page 49739]]
porpoise may be lower (Kastak et al. 2005; Southall et al. 2007; Lucke
et al. 2009). If so, TTS and potentially PTS may extend to a somewhat
greater distance for those animals. Again, Lloyd's mirror and surface
release effects will ameliorate the effects for animals at or near the
surface.
(5) Non-Auditory Physical Effects
Non-auditory physical effects might occur in marine mammals exposed
to strong underwater pulsed sound. Possible types of non-auditory
physiological effects or injuries that theoretically might occur in
mammals close to a strong sound source include stress, neurological
effects, bubble formation, and other types of organ or tissue damage.
Some marine mammal species (i.e., beaked whales) may be especially
susceptible to injury and/or stranding when exposed to intense sounds.
However, there is no definitive evidence that any of these effects
occur even for marine mammals in close proximity to large arrays of
airguns, and beaked whales do not occur in the proposed project area.
In addition, marine mammals that show behavioral avoidance of seismic
vessels, including most baleen whales, some odontocetes (including
belugas), and some pinnipeds, are especially unlikely to incur non-
auditory impairment or other physical effects. The small airgun array
proposed to be used by Shell would only have 190 and 180 dB distances
of 35 and 125 m (115 and 410 ft), respectively.
Therefore, it is unlikely that such effects would occur during
Shell's proposed surveys given the brief duration of exposure and the
planned monitoring and mitigation measures described later in this
document.
(6) Stranding and Mortality
Marine mammals close to underwater detonations of high explosive
can be killed or severely injured, and the auditory organs are
especially susceptible to injury (Ketten et al. 1993; Ketten 1995).
Airgun pulses are less energetic and their peak amplitudes have slower
rise times, while stranding and mortality events would include other
energy sources (acoustical or shock wave) far beyond just seismic
airguns. To date, there is no evidence that serious injury, death, or
stranding by marine mammals can occur from exposure to airgun pulses,
even in the case of large airgun arrays.
However, in numerous past IHA notices for seismic surveys,
commenters have referenced two stranding events allegedly associated
with seismic activities, one off Baja California and a second off
Brazil. NMFS has addressed this concern several times, and, without new
information, does not believe that this issue warrants further
discussion. For information relevant to strandings of marine mammals,
readers are encouraged to review NMFS' response to comments on this
matter found in 69 FR 74906 (December 14, 2004), 71 FR 43112 (July 31,
2006), 71 FR 50027 (August 24, 2006), and 71 FR 49418 (August 23,
2006). In addition, a May-June 2008, stranding of 100-200 melon-headed
whales (Peponocephala electra) off Madagascar that appears to be
associated with seismic surveys is currently under investigation (IWC
2009).
It should be noted that strandings related to sound exposure have
not been recorded for marine mammal species in the Beaufort and Chukchi
seas. NMFS notes that in the Beaufort Sea, aerial surveys have been
conducted by MMS and industry during periods of industrial activity
(and by MMS during times with no activity). No strandings or marine
mammals in distress have been observed during these surveys and none
have been reported by North Slope Borough inhabitants. As a result,
NMFS does not expect any marine mammals will incur serious injury or
mortality in the Arctic Ocean or strand as a result of proposed seismic
survey.
Potential Effects From Active Sonar Equipment on Marine Mammals
Several active acoustic sources other than the 40 cu-in airgun have
been proposed for Shell's 2010 open water marine surveys in the
Beaufort and Chukchi Seas. The specifications of these sonar equipments
(source levels and frequency ranges) are provided above. In general,
the potential effects of these equipments on marine mammals are similar
to those from the airgun, except the magnitude of the impacts is
expected to be much less due to the lower intensity and higher
frequencies. Estimated source levels and zones of influence from sonar
equipment are discussed above. In some cases, due to the fact that the
operating frequencies of some of this equipment (e.g., Multi-beam echo
sounder: frequency at 240 kHz) are above the hearing ranges of marine
mammals, use of the equipment is not expected to cause any take of
marine mammals.
Vessel Sounds
In addition to the noise generated from seismic airguns and active
sonar systems, various types of vessels will be used in the operations,
including source vessels and support vessels. Sounds from boats and
vessels have been reported extensively (Greene and Moore 1995;
Blackwell and Greene 2002; 2005; 2006). Numerous measurements of
underwater vessel sound have been performed in support of recent
industry activity in the Chukchi and Beaufort Seas. Results of these
measurements have been reported in various 90-day and comprehensive
reports since 2007 (e.g., Aerts et al. 2008; Hauser et al. 2008;
Brueggeman 2009; Ireland et al. 2009). For example, Garner and Hannay
(2009) estimated sound pressure levels of 100 dB at distances ranging
from approximately 1.5 to 2.3 mi (2.4 to 3.7 km) from various types of
barges. MacDonald et al. (2008) estimated higher underwater SPLs from
the seismic vessel Gilavar of 120 dB at approximately 13 mi (21 km)
from the source, although the sound level was only 150 dB at 85 ft (26
m) from the vessel. Compared to airgun pulses, underwater sound from
vessels is generally at relatively low frequencies.
The primary sources of sounds from all vessel classes are propeller
cavitation, propeller singing, and propulsion or other machinery.
Propeller cavitation is usually the dominant noise source for vessels
(Ross 1976). Propeller cavitation and singing are produced outside the
hull, whereas propulsion or other machinery noise originates inside the
hull. There are additional sounds produced by vessel activity, such as
pumps, generators, flow noise from water passing over the hull, and
bubbles breaking in the wake. Icebreakers contribute greater sound
levels during ice-breaking activities than ships of similar size during
normal operation in open water (Richardson et al. 1995). This higher
sound production results from the greater amount of power and propeller
cavitation required when operating in thick ice. Source levels from
various vessels would be empirically measured before the start of
marine surveys.
Anticipated Effects on Habitat
The primary potential impacts to marine mammals and other marine
species are associated with elevated sound levels produced by airguns
and other active acoustic sources. However, other potential impacts to
the surrounding habitat from physical disturbance are also possible.
Potential Impacts on Prey Species
With regard to fish as a prey source for cetaceans and pinnipeds,
fish are known to hear and react to sounds and to use sound to
communicate (Tavolga et al. 1981) and possibly avoid predators (Wilson
and Dill 2002). Experiments have shown that fish can sense both the
[[Page 49740]]
strength and direction of sound (Hawkins, 1981). Primary factors
determining whether a fish can sense a sound signal, and potentially
react to it, are the frequency of the signal and the strength of the
signal in relation to the natural background noise level.
The level of sound at which a fish will react or alter its behavior
is usually well above the detection level. Fish have been found to
react to sounds when the sound level increased to about 20 dB above the
detection level of 120 dB (Ona 1988); however, the response threshold
can depend on the time of year and the fish's physiological condition
(Engas et al. 1993). In general, fish react more strongly to pulses of
sound rather than a continuous signal (Blaxter et al. 1981), and a
quicker alarm response is elicited when the sound signal intensity
rises rapidly compared to sound rising more slowly to the same level.
Investigations of fish behavior in relation to vessel noise (Olsen
et al. 1983; Ona 1988; Ona and Godo 1990) have shown that fish react
when the sound from the engines and propeller exceeds a certain level.
Avoidance reactions have been observed in fish such as cod and herring
when vessels approached close enough that received sound levels are 110
dB to 130 dB (Nakken 1992; Olsen 1979; Ona and Godo 1990; Ona and
Toresen 1988). However, other researchers have found that fish such as
polar cod, herring, and capeline are often attracted to vessels
(apparently by the noise) and swim toward the vessel (Rostad et al.
2006). Typical sound source levels of vessel noise in the audible range
for fish are 150 dB to 170 dB (Richardson et al. 1995).
Some mysticetes, including bowhead whales, feed on concentrations
of zooplankton. Some feeding bowhead whales may occur in the Alaskan
Beaufort Sea in July and August, and others feed intermittently during
their westward migration in September and October (Richardson and
Thomson [eds.] 2002; Lowry et al. 2004). Reactions of zooplanktoners to
sound are, for the most part, not known. Their abilities to move
significant distances are limited or nil, depending on the type of
animal. A reaction by zooplankton to sounds produced by the marine
survey program would only be relevant to whales if it caused
concentrations of zooplankton to scatter. Pressure changes of
sufficient magnitude to cause that type of reaction would probably
occur only near the airgun source, which is expected to be a very small
area. Impacts on zooplankton behavior are predicted to be negligible,
and that would translate into negligible impacts on feeding mysticetes.
Estimated Take by Incidental Harassment
Except with respect to certain activities not pertinent here, the
MMPA defines ``harassment'' as: any act of pursuit, torment, or
annoyance which (i) has the potential to injure a marine mammal or
marine mammal stock in the wild [Level A harassment]; or (ii) has the
potential to disturb a marine mammal or marine mammal stock in the wild
by causing disruption of behavioral patterns, including, but not
limited to, migration, breathing, nursing, breeding, feeding, or
sheltering [Level B harassment]. Only take by Level B behavioral
harassment is anticipated as a result of the proposed open water marine
survey program. Anticipated take of marine mammals is associated with
noise propagation from the seismic airgun(s) used in the site clearance
and shallow hazards surveys.
The full suite of potential impacts to marine mammals was described
in detail in the ``Potential Effects of the Specified Activity on
Marine Mammals'' section found earlier in this document. The potential
effects of sound from the proposed open water marine survey programs
might include one or more of the following: tolerance; masking of
natural sounds; behavioral disturbance; non-auditory physical effects;
and, at least in theory, temporary or permanent hearing impairment
(Richardson et al. 1995). As discussed earlier in this document, the
most common impact will likely be from behavioral disturbance,
including avoidance of the ensonified area or changes in speed,
direction, and/or diving profile of the animal. For reasons discussed
previously in this document, hearing impairment (TTS and PTS) are
highly unlikely to occur based on the fact that most of the equipment
to be used during Shell's proposed open water marine survey programs do
not have received levels high enough to elicit even mild TTS beyond a
short distance. For instance, for the airgun sources, the 180- and 190-
dB re 1 [mu]Pa (rms) isopleths extend to 125 m and 35 m from the
source, respectively. None of the other active acoustic sources is
expected to have received levels above 180 dB re 1 [mu]Pa (rms) within
the frequency bands of marine mammal hearing sensitivity (below 180
kHz) beyond a few meters from the source. Finally, based on the
proposed mitigation and monitoring measures described earlier in this
document, no injury or mortality of marine mammals is anticipated as a
result of Shell's proposed open water marine survey programs.
For impulse sounds, such as those produced by airgun(s) used for
the site clearance and shallow hazards surveys, NMFS uses the 160 dB re
1 [mu]Pa (rms) isopleth to indicate the onset of Level B harassment.
Shell provided calculations for the 160-dB isopleths produced by these
active acoustic sources and then used those isopleths to estimate takes
by harassment. NMFS used these calculations to make the necessary MMPA
findings. Shell provides a full description of the methodology used to
estimate takes by harassment in its IHA application (see ADDRESSES),
which is also provided in the following sections.
Shell has requested an authorization to take individuals of 11
marine mammal species by Level B harassment. These 11 marine mammal
species are: beluga whale (Delphinapterus leucas), narwhal (Monodon
monoceros), harbor porpoise (Phocoena phocoena), bowhead whale (Balaena
mysticetus), gray whale (Eschrichtius robustus), humpback whale
(Megaptera novaeangliae), minke whale (Balaenoptera acutorostrata),
bearded seal (Erignathus barbatus), ringed seal (Phoca hispida),
spotted seal (P. largha), and ribbon seal (Histriophoca fasciata).
However, NMFS believes that narwhals, minke whales, and ribbon seals
are not likely to occur in the proposed survey area during the time of
the proposed site clearance and shallow hazards surveys. Therefore,
NMFS believes that only the other eight of the 11 marine mammal species
would likely be taken by Level B behavioral harassment as a result of
the proposed marine surveys.
Basis for Estimating ``Take by Harassment''
As stated previously, it is current NMFS policy to estimate take by
Level B harassment for impulse sounds as occurring when an animal is
exposed to a received level of 160 dB re 1 [mu]Pa (rms). However, not
all animals react to sounds at this low level, and many will not show
strong reactions (and in some cases any reaction) until sounds are much
stronger. Southall et al. (2007) provides a severity scale for ranking
observed behavioral responses of both free-ranging marine mammals and
laboratory subjects to various types of anthropogenic sound (see Table
4 in Southall et al. (2007)). Tables 7, 9, and 11 in Southall et al.
(2007) outline the numbers of low-frequency cetaceans, mid-frequency
cetaceans, and pinnipeds in water, respectively, reported as having
behavioral responses to multi-pulses in 10-dB received level
increments. These tables illustrate that
[[Page 49741]]
the more severe reactions did not occur until sounds were much higher
than 160 dB re 1 [mu]Pa (rms).
The proposed open water marine surveys would use low energy active
acoustic sources, including a total volume of 40 cu-in airgun or airgun
array. Other active acoustic sources used for ice gouging and strudel
scour all have relatively low source levels and/or high frequencies
beyond marine mammal hearing range. Table 1 depicts the modeled and/or
measured source levels, and radii for the 120, 160, 180, and 190 dB re
1 [mu]Pa (rms) from various sources (or equivalent) that are proposed
to be used in the marine mammal surveys by Shell.
Table 1. A list of active acoustic sources proposed to be used for
the Shell's 2010 open water marine surveys in the Chukchi and Beaufort
Seas
Table 1--A List of Active Acoustic Sources Proposed To Be Used for the Shell's 2010 Open Water Marine Surveys in the Chukchi and Beaufort Seas
--------------------------------------------------------------------------------------------------------------------------------------------------------
Radii (m) at modeled received levels (dB re 1
Modeled [micro]Pa)
Survey types Active acoustic sources Frequency source ---------------------------------------------------
level 190 180 160 120
--------------------------------------------------------------------------------------------------------------------------------------------------------
Site Clearance & Shallow Hazards..... 40 cu-in airgun........ ....................... 217 35 125 1,220 14,900
------------------------------------------------------------------------------------------------------------------
Dual frequency side 190 & 240 kHz.......... 225 Not modeled/measured because frequency outputs
scan. beyond marine mammal hearing range.
------------------------------------------------------------------------------------------------------------------
Single beam echo sound. 100-340 kHz............ 180-200 Not modeled/measured because majority of frequency
outputs beyond marine mammal hearing range.
------------------------------------------------------------------------------------------------------------------
Shallow sub-bottom 3.5 kHz (Alpha Helix).. 193.8 1 3 14 310
profiler.
-----------------------------------------------------------------------------------------
3.5 kHz (Henry C.)..... 167.2 NA NA 3 980
-----------------------------------------------------------------------------------------
400 Hz................. 176.8 NA NA 9 1,340
--------------------------------------------------------------------------------------------------------------------------------------------------------
Ice Gouging Surveys.................. Dual freq sub-bottom 2-7 kHz & 8-23 kHz..... 184.6 NA 2 7 456
profiler.
------------------------------------------------------------------------------------------------------------------
Multibeam Echo Sounder. 240 kHz................ Not modeled/measured because frequency outputs beyond marine
mammal hearing range.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Strudel Scour Survey................. Multibeam Echo Sounder. 240 kHz................ Not modeled/measured because frequency outputs beyond marine
mammal hearing range.
------------------------------------------------------------------------------------------------------------------
Single Beam Bathymetric > 200 kHz.............. 215 Not modeled/measured because frequency outputs
Sonar. beyond marine mammal hearing range.
--------------------------------------------------------------------------------------------------------------------------------------------------------
``Take by Harassment'' is calculated in this section and Shell's
application by multiplying the expected densities of marine mammals
that may occur in the site clearance and shallow hazards survey area by
the area of water body likely to be exposed to airgun impulses with
received levels of >=160 dB re 1 [mu]Pa (rms). The single exception to
this method is for the estimation of exposures of bowhead whales during
the fall migration where more detailed data were available allowing an
alternate approach, described below, to be used. This section describes
the estimated densities of marine mammals that may occur in the project
area. The area of water that may be ensonified to the above sound
levels is described further in the ``Potential Number of Takes by
Harassment'' subsection.
Marine mammal densities near the operation are likely to vary by
season and habitat. However, sufficient published data allowing the
estimation of separate densities during summer (July and August) and
fall (September and October) are only available for beluga and bowhead
whales. As noted above, exposures of bowhead whales during the fall are
not calculated using densities (see below). Therefore, summer and fall
densities have been estimated for beluga whales, and a summer density
has been estimated for bowhead whales. Densities of all other species
have been estimated to represent the duration of both seasons. The
estimated 30 days of site clearance and shallow hazards survey activity
will take place in eastern Harrison Bay at approximately five potential
prospective future drill sites. The survey lines form a grid or survey
``patch.'' It is expected that three of these patches will be surveyed
during the summer and two during the fall. The areas of water exposed
to sounds during surveys at the patches are separated by season in this
manner and as described further below.
Marine mammal densities are also likely to vary by habitat type. In
the Alaskan Beaufort Sea, where the continental shelf break is
relatively close to shore, marine mammal habitat is often defined by
water depth. Bowhead and beluga occurrence within nearshore (0-131 ft,
0-40 m), outer continental shelf (131-656 ft, 40-200 m), slope (656-
6,562 ft, 200-2,000 m), basin (>6,562 ft, 2,000 m), or similarly
defined habitats have been described previously (Moore et al. 2000;
Richardson and Thomson 2002). The presence of most other species has
generally only been described relative to the entire continental shelf
zone (0-656 ft, 0-200 m) or beyond. Sounds produced by the site
clearance and shallow hazards surveys are expected to drop below 160 dB
within the nearshore zone (0-131 ft, 0-40 m, water depth). Sounds >=160
dB are not expected to occur in waters >656 ft (200 m). Because airgun
sounds at the indicated levels would not be introduced to the outer
continental shelf, separate beluga and bowhead densities for the outer
continental shelf have not been used in the calculations.
[[Page 49742]]
In addition to water depth, densities of marine mammals are likely
to vary with the presence or absence of sea ice (see later for
descriptions by species). At times during either summer or fall, pack-
ice may be present in some of the area near Harrison Bay. However,
because some of the survey equipment towed behind the vessel may be
damaged by ice, site clearance and shallow hazards survey activities
will generally avoid sea-ice. Therefore, Shell has assumed that only
10% of the area exposed to sounds >=160 dB by the survey will be near
ice margin habitat. Ice-margin densities of marine mammals in both
seasons have therefore been multiplied by 10% of the area exposed to
sounds by the airguns, while open-water (nearshore) densities have been
multiplied by the remaining 90% of the area (see area calculations
below).
To provide some allowance for the uncertainties, Shell calculated
both ``maximum estimates'' as well as ``average estimates'' of the
numbers of marine mammals that could potentially be affected. For a few
marine mammal species, several density estimates were available, and in
those cases the mean and maximum estimates were determined from the
survey data. In other cases, no applicable estimate (or perhaps a
single estimate) was available, so correction factors were used to
arrive at ``average'' and ``maximum'' estimates. These are described in
detail in the following subsections. NMFS has determined that the
average density data of marine mammal populations will be used to
calculate estimated take numbers because these numbers are based on
surveys and monitoring of marine mammals in the vicinity of the
proposed project area. For several species whose average densities are
too low to yield a take number due to extra-limital distribution in the
vicinity of the proposed Beaufort Sea survey area, but whose chance
occurrence has been documented in the past, such as gray and humpback
whales and harbor porpoises, NMFS allotted a few numbers of these
species to allow unexpected takes of these species.
Detectability bias, quantified in part by f(0), is associated with
diminishing sightability with increasing lateral distance from the
trackline. Availability bias [g(0)] refers to the fact that there is
<100% probability of sighting an animal that is present along the
survey trackline. Some sources of densities used below included these
correction factors in their reported densities. In other cases the best
available correction factors were applied to reported results when they
had not been included in the reported data (e.g. Moore et al. 2000b).
(1) Cetaceans
As noted above, the densities of beluga and bowhead whales present
in the Beaufort Sea are expected to vary by season and location. During
the early and mid-summer, most belugas and bowheads are found in the
Canadian Beaufort Sea and Amundsen Gulf or adjacent areas. Low numbers
of bowhead whales, some of which are in feeding aggregations, are found
in the eastern Alaskan Beaufort Sea and the northeastern Chukchi Sea.
Belugas begin to move across the Alaskan Beaufort Sea in August, and
the majority of bowheads do so toward the end of August.
Beluga Whales--Beluga density estimates were derived from data in
Moore et al. (2000). During the summer, beluga whales are most likely
to be encountered in offshore waters of the eastern Alaskan Beaufort
Sea or areas with pack ice. The summer beluga whale nearshore density
was based on 11,985 km (7,749 mi) of on-transect effort and 9
associated sightings that occurred in water <=50 m (164 ft) in Moore et
al. (2000; Table 2). A mean group size of 1.63, a f(0) value of 2.841,
and a g(0) value of 0.58 from Harwood et al. (1996) were also used in
the calculation. Moore et al. (2000) found that belugas were equally
likely to occur in heavy ice conditions as open water or very light ice
conditions in summer in the Beaufort Sea, so the same density was used
for both nearshore and ice-margin estimates (Table 2). The fall beluga
whale nearshore density was based on 72,711 km (45,190 mi) of on-
transect effort and 28 associated sightings that occurred in water <=50
m (164 ft) reported in Moore et al. (2000). A mean group size of 2.9
(CV=1.9), calculated from all Beaufort Sea fall beluga sightings in
<=50 m (164 ft) of water present in the MMS Bowhead Whale Aerial Survey
Program (BWASP) database, along with the same f(0) and g(0) values from
Harwood et al. (1996) were also used in the calculation. Moore et al.
(2000) found that during the fall in the Beaufort Sea belugas occurred
in moderate to heavy ice at higher rates than in light ice, so ice-
margin densities were estimated to be twice the nearshore densities.
Based on the CV of group size maximum estimates in both season and
habitats were estimated as four times the average estimates. ``Takes by
harassment'' of beluga whales during the fall in the Beaufort Sea were
not calculated in the same manner as described for bowhead whales
(below) because of the relatively lower expected densities of beluga
whales in nearshore habitat near the site clearance and shallow hazards
surveys and the lack of detailed data on the likely timing and rate of
migration through the area (Table 3).
Table 2--Expected Summer (Jul-Aug) Densities of Beluga and Bowhead Whales in the Alaskan Beaufort Sea. Densities
Are Corrected for f(0) and g(0) Biases
----------------------------------------------------------------------------------------------------------------
Nearshore Ice margin
----------------------------------------------------------------------------------------------------------------
Species........................... Average Density (/km\2\).... Average Density (/km\2\).
Beluga whale...................... 0.0030............................... 0.0030.
Bowhead whale..................... 0.0186............................... 0.0186.
----------------------------------------------------------------------------------------------------------------
Table 3--Expected Fall (Sep-Nov) Densities of Beluga and Bowhead Whales in the Alaskan Beaufort Sea. Densities
Are Corrected for f(0) and g(0) Biases
----------------------------------------------------------------------------------------------------------------
Nearshore Ice margin
----------------------------------------------------------------------------------------------------------------
Species........................... Average Density (/km \2\)... Average Density (/km \2\).
Beluga whale...................... 0.0027............................... 0.0054.
Bowhead whale*.................... N/A.................................. N/A.
----------------------------------------------------------------------------------------------------------------
*See text for description of how bowhead whales estimates were made.
[[Page 49743]]
Bowhead Whales--Industry aerial surveys of the continental shelf
near Camden Bay in 2008 recorded eastward migrating bowhead whales
until July 12 (Lyons and Christie 2009). No bowhead sightings were
recorded again, despite continued flights, until August 19. Aerial
surveys by industry operators did not begin until late August of 2006
and 2007, but in both years bowheads were also recorded in the region
before the end of August (Christie et al. 2009). The late August
sightings were likely of bowheads beginning their fall migration so the
densities calculated from those surveys were not used to estimate
summer densities in this region. The three surveys in July 2008,
resulted in density estimates of 0.0099, 0.0717, and 0.0186 whales/km
\2\, respectively. The estimate of 0.0186 whales/km \2\ was used as the
average nearshore density, and the estimate of 0.0717 whales/km \2\ was
used as the maximum (Table 2). Sea ice was not present during these
surveys. Moore et al. (2000) reported that bowhead whales in the
Alaskan Beaufort Sea were distributed uniformly relative to sea ice, so
the same nearshore densities were used for ice-margin habitat.
During the fall most bowhead whales will be migrating west past the
site clearance and shallow hazards surveys, so it is less accurate to
assume that the number of individuals present in the area from one day
to the next will be static. However, feeding, resting, and milling
behaviors are not entirely uncommon at this time and location either.
In order to incorporate the movement of whales past the planned
operations, and because the necessary data are available, Shell has
developed an alternate method of calculating the number of individuals
exposed to sounds produced by the site clearance and shallow hazards
surveys. The method is founded on estimates of the proportion of the
population that would pass within the >=160 dB rms zones on a given day
in the fall during survey activities.
Approximately 10 days of site clearance and shallow hazards survey
activity are likely to occur during the fall period when bowheads are
migrating through the Beaufort Sea. If the bowhead population has
continued to grow at an annual rate of 3.4%, the current population
size would be approximately 14,247 individuals based on a 2001
population of 10,545 (Zeh and Punt 2005). Based on data in Richardson
and Thomson (2002, Appendix 9.1), the number of whales expected to pass
each day was estimated as a proportion of the population. Minimum and
maximum estimates of the number of whales passing each day were not
available, so a single estimate based on the 10-day moving average
presented by Richardson and Thomson (2002) was used. Richardson and
Thomson (2002) also calculated the proportion of animals within water
depth bins (<20 m, 20-40 m, 40-200 m, >200 m; or <65 ft, 65-131 ft,
131-656 ft, >656 ft). Using this information the total number of whales
expected to pass the site clearance and shallow hazards surveys each
day was multiplied by the proportion of whales that would be in each
depth category to estimate how many individuals would be within each
depth bin on a given day. The proportion of each depth bin falling
within the >=160 dB rms zone was then multiplied by the number of
whales within the respective bins to estimate the total number of
individuals that would be exposed on each day. This was repeated for a
total of 10 days (September 15-19 and October 1-4) and the results were
summed to estimate the total number of bowhead whales that might be
exposed to >=160 dB rms during the migration period in the Beaufort
Sea.
Other Cetaceans--For other cetacean species that may be encountered
in the Beaufort Sea, densities are likely to vary somewhat by season,
but differences are not expected to be great enough to require
estimation of separate densities for the two seasons. Harbor porpoises
and gray whales are not expected to be present in large numbers in the
Beaufort Sea during the fall but small numbers may be encountered
during the summer. They are most likely to be present in nearshore
waters (Table 4). Narwhals are not expected to be encountered during
the site clearance and shallow hazards surveys. However, there is a
chance that a few individuals may be present if ice is nearby. The
first record of humpback whales in the Beaufort Sea was documented in
2007 so their presence cannot be ruled out. Since these species occur
so infrequently in the Beaufort Sea, little to no data are available
for the calculation of densities. Minimal densities have therefore been
assigned for calculation purposes and to allow for chance encounters
(Table 4).
Table 4. Expected Densities of Cetaceans (Excluding Beluga and Bowhead Whale) and Seals in the Alaskan Beaufort
Sea
----------------------------------------------------------------------------------------------------------------
Nearshore Ice margin
----------------------------------------------------------------------------------------------------------------
Average density (/km Average density (/km
Species \2\) \2\)
----------------------------------------------------------------------------------------------------------------
Narwhal........................................... 0.0000 0.0000
Harbor porpoise................................... 0.0001 0.0000
Gray whale........................................ 0.0001 0.0000
Bearded seal...................................... 0.0181 0.0128
Ribbon seal....................................... 0.0001 0.0001
Ringed seal....................................... 0.3547 0.2510
Spotted seal...................................... 0.0037 0.0001
----------------------------------------------------------------------------------------------------------------
(2) Pinnipeds
Extensive surveys of ringed and bearded seals have been conducted
in the Beaufort Sea, but most surveys have been conducted over the
landfast ice, and few seal surveys have occurred in open-water or in
the pack ice. Kingsley (1986) conducted ringed seal surveys of the
offshore pack ice in the central and eastern Beaufort Sea during late
spring (late June). These surveys provide the most relevant information
on densities of ringed seals in the ice margin zone of the Beaufort
Sea. The density estimate in Kingsley (1986) was used as the average
density of ringed seals that may be encountered in the ice margin
(Table 6-3 in Shell's application and Table 4 here). The average ringed
seal density in the nearshore zone of the Alaskan Beaufort Sea was
estimated from results of ship-based surveys at times without seismic
operations reported by Moulton and Lawson (2002; Table 6-3 in Shell's
application and Table 4 here).
Densities of bearded seals were estimated by multiplying the ringed
seal densities by 0.051 based on the proportion of bearded seals to
ringed seals reported in Stirling et al. (1982;
[[Page 49744]]
Table 6-3 in Shell's application and Table 4 here). Spotted seal
densities in the nearshore zone were estimated by summing the ringed
seal and bearded seal densities and multiplying the result by 0.015
based on the proportion of spotted seals to ringed plus bearded seals
reported in Moulton and Lawson (2002; Table 6-3 in Shell's application
and Table 4 here). Minimal values were assigned as densities in the
ice-margin zones (Table 6-3 in Shell's application and Table 4 here).
Potential Number of Takes by Harassment
Numbers of marine mammals that might be present and potentially
disturbed are estimated below based on available data about mammal
distribution and densities at different locations and times of the year
as described previously. The planned site clearance and shallow hazards
survey would take place in the Beaufort Sea over two different seasons.
The estimates of marine mammal densities have therefore been separated
both spatially and temporarily in an attempt to represent the
distribution of animals expected to be encountered over the duration of
the site clearance and shallow hazards survey.
The number of individuals of each species potentially exposed to
received levels >=160 dB re 1 [mu]Pa (rms) within each season and
habitat zone was estimated by multiplying
the anticipated area to be ensonified to the specified
level in each season and habitat zone to which that density applies, by
the expected species density.
The numbers of potential individuals exposed were then summed for
each species across the two seasons and habitat zones. Some of the
animals estimated to be exposed, particularly migrating bowhead whales,
might show avoidance reactions before being exposed to >=160 dB re 1
[mu]Pa (rms). Thus, these calculations actually estimate the number of
individuals potentially exposed to >=160 dB that would occur if there
were no avoidance of the area ensonified to that level.
The area of water potentially exposed to received levels >=160 dB
re 1 [mu]Pa (rms) by airgun operations was calculated by buffering a
typical site clearance and shallow hazards survey grid of lines by the
estimated >160 dB distance from the airgun source, including turns
between lines during which a single mitigation airgun will be active.
Measurements of a 2 x 10 in\3\ airgun array used in 2007 were reported
by Funk et al. (2008). These measurements were used to model both of
the potential airgun arrays that may be used in 2010, a 4 x 10 in\3\
array or a 2 x 10 in\3\ + 1 x 20 in\3\ array. The modeling results
showed that the 40 cubic inch array is likely to produce sound that
propagates further than the alternative array, so those results were
used. The modeled 160 dB re 1 [mu]Pa (rms) distance from a 40 cubic
inch array was 1,220 m (4,003 ft) from the source. Because this is a
modeled estimate, but based on similar measurements at the same
location, the estimated distance was only increased by a factor of 1.25
instead of a typical 1.5 factor. This results in a 160 dB distance of
1,525 m (5,003 ft) which was added to both sides of the survey lines in
a typical site clearance and shallow hazards survey grid. The resulting
area that may be exposed to airgun sounds >=160 dB re 1 [mu]Pa (rms) is
81.6 km\2\. In most cases the use of a single mitigation gun during
turns will not appreciably increase the total area exposed to sounds
>=160 dB re 1 [mu]Pa (rms), but analysis of a similar survey pattern
from the Chukchi Sea (but using the Beaufort sound radii) suggested use
of the mitigation gun may increase this area to 82.3 km\2\. As
described above, three patches (246.9 km\2\) are likely to be surveyed
during the summer leaving two (164.6 km\2\) for the fall. During both
seasons, 90% of the area has been multiplied by nearshore (open-water)
densities, and the remaining 10% by the ice-margin densities.
For analysis of potential effects on migrating bowhead whales we
calculated the maximum distance perpendicular to the migration path
ensonified to >=160 dB re 1 [mu]Pa (rms) by a typical survey patch as
11.6 km (7.2 mi). This distance represents approximately 21% of the 56
km (34.8 mi) between the barrier islands and the 40-m (131-ft)
bathymetry line so it was assumed that 21% of the bowheads migrating
within the nearshore zone (water depth 0-40 m, or 0-131 ft) may be
exposed to sounds >=160 dB re 1 [mu]Pa (rms) if they showed no
avoidance of the site clearance and shallow hazards survey activities.
Cetaceans--Cetacean species potentially exposed to airgun sounds
with received levels >=160 dB re 1 [mu]Pa (rms) would involve bowhead,
gray, humpback, and beluga whales and harbor porpoises. Shell also
included some maximum exposure estimates for narwhal and minke whale.
However, as stated previously in this document, NMFS has determined
that authorizing take of these two cetacean species is not warranted
given the highly unlikely potential of these species to occur in the
open water marine survey area. The average estimates of the number of
individual bowhead whales exposed to received sound levels >=160 dB re
1 [mu]Pa (rms) is 381 and belugas is 1 individual. However, since
beluga whales often form small groups, it is likely that the exposure
to the animals would be based on groups instead of individual animals.
Therefore, NMFS proposes to make an adjustment to increase the number
of beluga whale takes to 5 individuals to reflect the aggregate nature
of these animals.
The estimates show that one endangered cetacean species (the
bowhead whale) is expected to be exposed to sounds >=160 dB re 1 [mu]Pa
(rms) unless bowheads avoid the area around the site clearance and
shallow hazards survey areas (Tables 4). Migrating bowheads are likely
to do so to some extent, though many of the bowheads engaged in other
activities, particularly feeding and socializing, probably will not.
As discussed before, although no take estimates of gray and
humpback whales and harbor porpoises can be calculated due to their low
density and extralimital distribution in the vicinity of the site
clearance and shallow hazards survey area in the Beaufort Sea, their
occurrence has been documented in the past. Therefore, to allow for
chance encounters of these species, NMFS proposes to include two
individuals of each of these three species as having the potential to
be exposed to an area with received levels >=160 dB re 1 [mu]Pa (rms).
Pinnipeds--The ringed seal is the most widespread and abundant
pinniped in ice-covered arctic waters, and there appears to be a great
deal of year-to-year variation in abundance and distribution of these
marine mammals. Ringed seals account for a large number of marine
mammals expected to be encountered during the site clearance and
shallow hazard survey activities, and hence exposed to sounds with
received levels >=160 dB re 1 [mu]Pa (rms). The average estimate is
that 567 ringed seals might be exposed to sounds with received levels
>=160 dB re 1 [mu]Pa (rms) from airgun impulses.
Two additional seal species are expected to be encountered. Average
estimates for bearded seal exposures to sound levels >=160 dB re
1[mu]Pa (rms) is 7 individuals. For spotted seal the exposure estimates
is 1 individual.
Table 5 summarizes the number of potential takes by harassment of
all species.
[[Page 49745]]
Table 5--Summary of the Number of Potential Exposures of Marine Mammals
to Received Sound Levels in the Water of >=160 dB During Shell's Planned
Site Clearance and Shallow Hazards Surveys near Harrison Bay in the
Beaufort Sea, Alaska, July--October, 2010
------------------------------------------------------------------------
Total number of exposure to
Species sound levels >160 dB re 1
[mu]Pa (rms)
------------------------------------------------------------------------
Beluga whale........................... 5
Harbor porpoise........................ 2
Bowhead whale.......................... 381
Gray whale............................. 2
Humpback whale......................... 2
Bearded seal........................... 7
Ringed seal............................ 142
Spotted seal........................... 1
------------------------------------------------------------------------
Estimated Take Conclusions
Cetaceans--Effects on cetaceans are generally expected to be
restricted to avoidance of an area around the site clearance and
shallow hazards surveys and short-term changes in behavior, falling
within the MMPA definition of ``Level B harassment''.
Using the 160 dB criterion, the average estimates of the numbers of
individual cetaceans exposed to sounds >=160 dB re 1 [mu]Pa (rms)
represent varying proportions of the populations of each species in the
Beaufort Sea and adjacent waters. For species listed as ``Endangered''
under the ESA, the estimates include approximately 381 bowheads. This
number is approximately 2.7% of the Bering-Chukchi-Beaufort population
of >14,247 assuming 3.4% annual population growth from the 2001
estimate of >10,545 animals (Zeh and Punt 2005). The small numbers of
other mysticete whales that may occur in the Beaufort Sea are unlikely
to occur near the planned site clearance and shallow hazards surveys.
The few that might occur would represent a very small proportion of
their respective populations. The average estimate of the number of
belugas that might be exposed to >=160 dB re 1 [mu]Pa (rms) (1, with
adjustment to 5 considering group occurrence) represents <1% of its
population.
Seals--A few seal species are likely to be encountered in the study
area, but ringed seal is by far the most abundant in this area. The
average estimates of the numbers of individuals exposed to sounds at
received levels >=160 dB re 1 [mu]Pa (rms) during the site clearance
and shallow hazards surveys are as follows: ringed seals (142), bearded
seals (7), and spotted seals (1), (representing <1% of their respective
Beaufort Sea populations).
Impact on Availability of Affected Species or Stock for Taking for
Subsistence Uses
Relevant Subsistence Uses
The disturbance and potential displacement of marine mammals by
sounds from the proposed marine surveys are the principal concerns
related to subsistence use of the area. Subsistence remains the basis
for Alaska Native culture and community. Marine mammals are legally
hunted in Alaskan waters by coastal Alaska Natives. In rural Alaska,
subsistence activities are often central to many aspects of human
existence, including patterns of family life, artistic expression, and
community religious and celebratory activities. Additionally, the
animals taken for subsistence provide a significant portion of the food
that will last the community throughout the year. The main species that
are hunted include bowhead and beluga whales, ringed, spotted, and
bearded seals, walruses, and polar bears. (Both the walrus and the
polar bear are under the USFWS' jurisdiction.) The importance of each
of these species varies among the communities and is largely based on
availability.
The subsistence communities in the Beaufort and Chukchi Seas that
have the potential to be impacted by Shell's proposed open water marine
surveys include Kaktovik, Nuiqsut, Barrow, Wainwright, and Point Lay.
Kaktovik is a coastal community near the east boundary of the proposed
ice gouging area. Nuiqsut is approximately 30 mi (50 km) inland from
the proposed site clearance and shallow hazards survey area. Cross
Island, from which Nuiqsut hunters base their bowhead whaling
activities, is approximately 44 mi (70 km) east of the proposed site
clearance and shallow hazards survey area. Barrow lies approximately
168 mi (270 km) west of Shell's Harrison Bay site clearance and shallow
hazards survey areas. Wainwright is a coastal community approximately
12 mi (20 km) to the southeast boundary of the proposed ice gouging
survey area in the Chukchi Sea. Point Lay is another coastal community
boarding the southwest boundary of the proposed ice gouging survey area
in the Chukchi Sea. Point Hope is the western tip of the North Slope
and is approximately 124 mi (200 km) southwest of Shell's proposed ice
gouge survey area in the Chukchi Sea.
(1) Bowhead Whales
Of the three communities along the Beaufort Sea coast, Barrow is
the only one that currently participates in a spring bowhead whale
hunt. However, this hunt is not anticipated to be affected by Shell's
activities, as the spring hunt occurs in late April to early May, and
Shell's marine surveys in Beaufort Sea will not begin until July at the
earliest.
All three communities participate in a fall bowhead hunt. In
autumn, westward-migrating bowhead whales typically reach the Kaktovik
and Cross Island (Nuiqsut hunters) areas by early September, at which
point the hunts begin (Kaleak 1996; Long 1996; Galginaitis and Koski
2002; Galginaitis and Funk 2004, 2005; Koski et al. 2005). Around late
August, the hunters from Nuiqsut establish camps on Cross Island from
where they undertake the fall bowhead whale hunt. The hunting period
starts normally in early September and may last as late as mid-October,
depending mainly on ice and weather conditions and the success of the
hunt. Most of the hunt occurs offshore in waters east, north, and
northwest of Cross Island where bowheads migrate and not inside the
barrier islands (Galginaitis 2007). Hunters prefer to take bowheads
close to shore to avoid a long tow, but Braund and Moorehead (1995)
report that crews may (rarely) pursue whales as far as 50 mi (80 km)
offshore. Whaling crews use Kaktovik as their home base, leaving the
village and returning on a daily basis. The core whaling area is within
12 mi (19.3 km) of the village with a periphery ranging about 8 mi (13
km) farther, if necessary. The extreme limits of the Kaktovik whaling
hunt would be the middle of Camden Bay to the west. The timing of the
Kaktovik bowhead whale hunt roughly parallels the Cross Island whale
hunt (Impact Assessment Inc 1990b; SRB&A 2009: Map 64). In recent
years, the hunts at Kaktovik and Cross Island have usually ended by
mid- to late September.
Westbound bowheads typically reach the Barrow area in mid-
September, and are in that area until late October (Brower 1996).
However, over the years, local residents report having seen a small
number of bowhead whales feeding off Barrow or in the pack ice off
Barrow during the summer. Recently, autumn bowhead whaling near Barrow
has normally begun in mid-September to early October, but in earlier
years it began as early as August if whales were observed and ice
conditions were favorable (USDI/BLM 2005). The recent decision to delay
harvesting whales
[[Page 49746]]
until mid-to-late September has been made to prevent spoilage, which
might occur if whales were harvested earlier in the season when the
temperatures tend to be warmer. Whaling near Barrow can continue into
October, depending on the quota and conditions.
Along the Chukchi Sea, the spring bowhead whale hunt for Wainwright
occurs between April and June in leads offshore from the village.
Whaling camps can be located up to 16-24 km (10-15 mi) from shore,
depending on where the leads open up. Whalers prefer to be closer,
however, and will sometimes go overland north of Wainwright to find
closer leads (SRBA 1993). Residents of Point Lay have not hunted
bowhead whales in the recent past, but were selected by the
International Whaling Commission (IWC) to receive a bowhead whale quota
in 2009, and began bowhead hunting again in 2009. In the more distant
past, Point Lay hunters traveled to Barrow, Wainwright, or Point Hope
to participate in the bowhead whale harvest activities. In Point Hope,
the bowhead whale hunt occurs between March and June, when the pack-ice
lead is usually 10-11 km (6-7 mi) offshore. Camps are set up along the
landfast ice edge to the south and southeast of the village. Point Hope
whalers took between one and seven bowhead whales per year between 1978
and 2008, with the exception of 1980, 1989, 2002, and 2006, when no
whales were taken (Suydam and George 2004; Suydam et al. 2008, 2007,
2006, 2005). There is no fall bowhead hunt in Point Hope, as the whales
migrate back down on the west side of the Bering Strait, out of range
of the Point Hope whalers (Fuller and George 1997).
(2) Beluga Whales
Beluga whales are not a prevailing subsistence resource in the
communities of Kaktovik and Nuiqsut. Kaktovik hunters may harvest one
beluga whale in conjunction with the bowhead hunt; however, it appears
that most households obtain beluga through exchanges with other
communities. Although Nuiqsut hunters have not hunted belugas for many
years while on Cross Island for the fall hunt, this does not mean that
they may not return to this practice in the future. Data presented by
Braund and Kruse (2009) indicate that only one percent of Barrow's
total harvest between 1962 and 1982 was of beluga whales and that it
did not account for any of the harvested animals between 1987 and 1989.
There has been minimal harvest of beluga whales in Beaufort Sea
villages in recent years. Additionally, if belugas are harvested, it is
usually in conjunction with the fall bowhead harvest. Shell will not be
operating during the Kaktovik and Nuiqsut fall bowhead harvests.
In the Chukchi communities, the spring beluga hunt by Wainwright
residents is concurrent with the bowhead hunt, but belugas are
typically taken only during the spring hunt if bowheads are not present
in the area. Belugas are also hunted later in the summer, between July
and August, along the coastal lagoon systems. Belugas are usually taken
less than 16 km (10 mi) from shore. Beluga whales are harvested in June
and July by Point Lay residents. They are taken in the highest numbers
in Naokak and Kukpowruk Passes south of Point Lay, but hunters will
travel north to Utukok Pass and south to Cape Beaufort in search of
belugas. The whales are usually herded by hunters with their boats into
the shallow waters of Kasegaluk Lagoon (MMS 2007). In Point Hope,
belugas are also hunted in the spring, coincident with the spring
bowhead hunt. A second hunt takes place later in the summer, in July
and August, and can extend into September, depending on conditions and
the IWC quota. The summer hunt is conducted in open water along the
coastline on either side of Point Hope, as far north as Cape Dyer (MMS
2007). Belugas are smaller than bowhead whales, but beluga whales often
make up a significant portion of the total harvest for Point Hope
(Fuller and George 1997; SRBA 1993). Ninety-eight belugas harvested in
1992 made up 40.3% of the total edible harvest for that year. Three
bowhead whales represented 6.9% of the total edible harvest for the
same year (Fuller and George 1997).
(3) Ice Seals
Ringed seals are available to subsistence users in the Beaufort Sea
year-round, but they are primarily hunted in the winter or spring due
to the rich availability of other mammals in the summer. Bearded seals
are primarily hunted during July in the Beaufort Sea; however, in 2007,
bearded seals were harvested in the months of August and September at
the mouth of the Colville River Delta. An annual bearded seal harvest
occurs in the vicinity of Thetis Island in July through August.
Approximately 20 bearded seals are harvested annually through this
hunt. Spotted seals are harvested by some of the villages in the summer
months. Nuiqsut hunters typically hunt spotted seals in the nearshore
waters off the Colville River delta, which drains into Harrison Bay,
where Shell's proposed site clearance and shallow hazards surveys are
planned.
Although there is the potential for some of the Beaufort villages
to hunt ice seals during the summer and fall months while Shell is
conducting marine surveys, the primary sealing months occur outside of
Shell's operating time frame.
In the Chukchi Sea, seals are most often taken between May and
September by Wainwright residents. Wainwright hunters will travel as
far south as Kuchaurak Creek (south of Point Lay) and north to Peard
Bay. Hunters typically stay within 72 km (45 mi) of the shore. Ringed
and bearded seals are harvested all year by Point Lay hunters. Ringed
seals are hunted 32 km (20 mi) north of Point Lay, as far as 40 km (25
mi) offshore. Hunters travel up to 48 m (30 mi) north of the community
for bearded seals, which are concentrated in the Solivik Island area.
Bearded seals are also taken south of the community in Kasegaluk
Lagoon, and as far as 40 km (25 mi) from shore. Seals are harvested
throughout most of the year by the Point Hope community, although they
tend to be taken in the greatest numbers in the winter and spring
months. The exception is the bearded seal hunt, which peaks later in
the spring and into the summer (Fuller and George 1997; MMS 2007).
Species of seals harvested by Point Hope hunters include ringed,
spotted, and bearded. Seals are hunted on the ice (Fuller and George
1997). Hunters tend to stay close to the shore but will travel up to 24
km (15 mi) offshore south of the point, weather dependent. Seals are
hunted to the north of the community as well, but less often, as the
ice is less stable and can be dangerous. Seals are taken between
Akoviknak Lagoon to the south and Ayugatak Lagoon to the north (MMS
2007).
Potential Impacts to Subsistence Uses
NMFS has defined ``unmitigable adverse impact'' in 50 CFR 216.103
as:
* * * an impact resulting from the specified activity: (1) That
is likely to reduce the availability of the species to a level
insufficient for a harvest to meet subsistence needs by: (i) Causing
the marine mammals to abandon or avoid hunting areas; (ii) Directly
displacing subsistence users; or (iii) Placing physical barriers
between the marine mammals and the subsistence hunters; and (2) That
cannot be sufficiently mitigated by other measures to increase the
availability of marine mammals to allow subsistence needs to be met.
Noise and general activity during Shell's proposed open water
marine surveys have the potential to impact marine mammals hunted by
Native
[[Page 49747]]
Alaskans. In the case of cetaceans, the most common reaction to
anthropogenic sounds (as noted previously in this document) is
avoidance of the ensonified area. In the case of bowhead whales, this
often means that the animals divert from their normal migratory path by
several kilometers. Additionally, general vessel presence in the
vicinity of traditional hunting areas could negatively impact a hunt.
In the case of subsistence hunts for bowhead whales in the Beaufort
and Chukchi Seas, there could be an adverse impact on the hunt if the
whales were deflected seaward (further from shore) in traditional
hunting areas. The impact would be that whaling crews would have to
travel greater distances to intercept westward migrating whales,
thereby creating a safety hazard for whaling crews and/or limiting
chances of successfully striking and landing bowheads.
Plan of Cooperation (POC or Plan)
Regulations at 50 CFR 216.104(a)(12) require IHA applicants for
activities that take place in Arctic waters to provide a POC or
information that identifies what measures have been taken and/or will
be taken to minimize adverse effects on the availability of marine
mammals for subsistence purposes.
Shell's POC is also subject to MMS Lease Sale Stipulation No. 5,
which requires that all exploration operations be conducted in a manner
that prevents unreasonable conflicts between oil and gas activities and
the subsistence activities and resources of residents of the North
Slope.
The POC identifies the measures that Shell has developed in
consultation with North Slope subsistence communities and will
implement during its planned 2010 site clearance and shallow hazards
surveys and ice gouge surveys to minimize any adverse effects on the
availability of marine mammals for subsistence uses. In addition, the
POC details Shell's communications and consultations with local
subsistence communities concerning its planned 2010 program, potential
conflicts with subsistence activities, and means of resolving any such
conflicts. Shell states that through its Subsistence Advisor (SA) and
Com and Call Center (Com Center) program for 2010, Shell's SA and Shell
representatives in the Com Centers will be available daily to the
communities throughout the 2010 season. The SA and Com Center programs
provide residents of the nearest affected communities a way to
communicate where and when subsistence activities so that industry may
avoid conflicts with planned subsistence activities. Shell continues to
document its contacts with the North Slope subsistence communities, as
well as the substance of its communications with subsistence
stakeholder groups.
Shell states that the POC will be, and has been in the past, the
result of numerous meetings and consultations between Shell, affected
subsistence communities and stakeholders, and federal agencies. The POC
identifies and documents potential conflicts and associated measures
that will be taken to minimize any adverse effects on the availability
of marine mammals for subsistence use. Outcomes of POC meetings are
attached to the POC as addenda and were distributed to Federal, State,
and local agencies as well as local stakeholder groups that either
adjudicate or influence mitigation approaches for Shell's open water
programs.
Meetings for Shell's 2010 program in the Beaufort and Chukchi Seas
were conducted for Nuiqsut, Kaktovik, Barrow, Point Hope, Point Lay,
Wainwright, and Kotzebue in the 1st quarter of 2010. Shell met with the
marine mammal commissions and committees including the Alaska Eskimo
Whaling Commission, Eskimo Walrus Commission, Alaska Beluga Whale
Committee, Alaska Ice Seal Committee, and the Alaska Nanuuq Commission
on December 8, 2009 in co-management meeting. Throughout 2010 Shell
anticipates continued engagement with the marine mammal commissions and
committees active in the subsistence harvests and marine mammal
research.
Following the 2010 season, Shell intends to have a post-season co-
management meeting with the commissioners and committee heads to
discuss results of mitigation measures and outcomes of the preceding
season. The goal of the post-season meeting is to build upon the
knowledge base, discuss successful or unsuccessful outcomes of
mitigation measures, and possibly refine plans or mitigation measures
if necessary.
Mitigation Measures
In order to issue an incidental take authorization under Section
101(a)(5)(D) of the MMPA, NMFS must set forth the permissible methods
of taking pursuant to such activity, and other means of effecting the
least practicable adverse impact on such species or stock and its
habitat, paying particular attention to rookeries, mating grounds, and
areas of similar significance, and on the availability of such species
or stock for taking for certain subsistence uses.
For Shell's proposed open water marine surveys in the Beaufort and
Chukchi Sea, Shell worked with NMFS and proposed the following
mitigation measures to minimize the potential impacts to marine mammals
in the project vicinity as a result of the marine survey activities.
As part of the application, Shell submitted to NMFS a Marine Mammal
Monitoring and Mitigation Program (4MP) for its shallow hazards survey
activities in the Beaufort Sea during the 2010 open-water season. The
objectives of the 4MP are:
To ensure that disturbance to marine mammals and
subsistence hunts is minimized and all permit stipulations are
followed,
To document the effects of the proposed survey activities
on marine mammals, and
To collect baseline data on the occurrence and
distribution of marine mammals in the study area.
For the proposed Shell's 2010 open water marine survey program in
the Beaufort and Chukchi Seas, the following mitigation measures are
required.
(1) Sound Source Measurements
As described above, previous measurements of airguns in the
Harrison Bay area were used to model the distances at which received
levels are likely to fall below 160, 180, and 190 dB re 1 [mu]Pa (rms)
from the planned airgun sources. These modeled distances will be used
as temporary safety radii until measurements of the airgun sound source
are conducted. The measurements will be made at the beginning of the
field season and the measured radii used for the remainder of the
survey period.
The objectives of the sound source verification measurements
planned for 2010 in the Beaufort Sea will be to measure the distances
in the broadside and endfire directions at which broadband received
levels reach 190, 180, 170, 160, and 120 dB re 1 [mu]Pa (rms) for the
energy source array combinations that may be used during the survey
activities. The configurations will include at least the full array and
the operation of a single source that will be used during power downs.
The measurements of energy source array sounds will be made at the
beginning of the survey and the distances to the various radii will be
reported as soon as possible after recovery of the equipment. The
primary radii of concern will be the 190 and 180 dB safety radii for
pinnipeds and cetaceans, respectively, and the 160 dB disturbance
radii. In addition to
[[Page 49748]]
reporting the radii of specific regulatory concern, nominal distances
to other sound isopleths down to 120 dB re 1 [mu]Pa (rms) will be
reported in increments of 10 dB.
Data will be previewed in the field immediately after download from
the ocean bottom hydrophone (OBH) instruments. An initial sound source
analysis will be supplied to NMFS and the airgun operators within 120
hours of completion of the measurements, if possible. The report will
indicate the distances to sound levels between 190 dB re 1 [mu]Pa (rms)
and 120 dB re 1 [mu]Pa (rms) based on fits of empirical transmission
loss formulae to data in the endfire and broadside directions. The 120-
hour report findings will be based on analysis of measurements from at
least three of the OBH systems. A more detailed report including
analysis of data from all OBH systems will be issued to NMFS as part of
the 90-day report following completion of the acoustic program.
Airgun pressure waveform data from the OBH systems will be analyzed
using JASCO's suite of custom signal processing software that
implements the following data processing steps:
Energy source pulses in the OBH recordings are identified
using an automated detection algorithm. The algorithm also chooses the
90% energy time window for rms sound level computations.
Waveform data is converted to units of [mu]Pa using the
calibrated acoustic response of the OBH system. Gains for frequency-
dependent hydrophone sensitivity, amplifier and digitizer are applied
in this step.
For each pulse, the distance to the airgun array is
computed from GPS deployment positions of the OBH systems and the time
referenced DGPS navigation logs of the survey vessel.
The waveform data are processed to determine flat-weighted
peak sound pressure level (PSPL), rms SPL and SEL.
Each energy pulse is Fast Fourier Transformed (FFT) to
obtain 1-Hz spectral power levels in 1-second steps.
The spectral power levels are integrated in standard 1/3-
octave bands to obtain band sound pressure levels (BSPL) for bands from
10 Hz to 20 kHz. Both un-weighted and M-weighted (frequency weighting
based on hearing sensitivities of four marine mammal functional hearing
groups, see Southall et al. (2007) for a review) SPL's for each airgun
pulse may be computed in this step for species of interest.
The output of the above data processing steps includes listings and
graphs of airgun array narrow band and broadband sound levels versus
range, and spectrograms of shot waveforms at specified ranges. Of
particular importance are the graphs of level versus range that are
used to compute representative radii to specific sound level
thresholds.
Power density spectra (frequency spectra) of high frequency active
acoustic sources (operating frequency >180 kHz) that will be used in
Shell's marine surveys will also be measured against ambient background
noise levels and reported in 1/3-octave band and 1-Hz band from 10 Hz
to 180 kHz. The purpose for this measurement is to determine whether
there is any acoustic energy within marine mammal hearing ranges that
would be generated from operating these high frequency acoustic
sources.
(2) Safety and Disturbance Zones
Under current NMFS guidelines, ``safety radii'' for marine mammal
exposure to impulse sources are customarily defined as the distances
within which received sound levels are >=180 dB re 1 [mu]Pa (rms) for
cetaceans and >=190 dB re 1 [mu]Pa (rms) for pinnipeds. These safety
criteria are based on an assumption that SPL received at levels lower
than these will not injure these animals or impair their hearing
abilities, but that SPL received at higher levels might have some such
effects. Disturbance or behavioral effects to marine mammals from
underwater sound may occur after exposure to sound at distances greater
than the safety radii (Richardson et al. 1995).
Initial safety and disturbance radii for the sound levels produced
by the survey activities have been modeled. These radii will be used
for mitigation purposes until results of direct measurements are
available early during the exploration activities. The planned survey
will use an airgun source composed of either 40 in\3\ airguns or 1 x
20-in\3\ plus 2 x 10-in\3\ airguns. The total source volume will be 4 x
10 in\3\. Measurements of a 2 x 10-in\3\ airgun array used in 2007 were
reported by Funk et al. (2008). These measurements were used as the
basis for modeling both of the potential airgun arrays that may be used
in 2010. The modeling results showed that the 40 in\3\ array is likely
to produce sounds that propagate further than the alternative array, so
those results were used to estimate ``takes by harassment'' in Shell's
IHA application and will also be used during initial survey activities
prior to in-field sound source measurements. The modeled 190 and 180 dB
distances from a 40 cubic inch array were 35 and 125 m, respectively.
Because this is a modeled estimate, but based on similar measurements
at the same location, the estimated distances for initial safety radii
were only increased by a factor of 1.25 instead of a typical 1.5
factor. This results in a 190-dB distance of 44 m and a 180-dB distance
of 156 m.
A single 10-in\3\ airgun will be used as a mitigation gun during
turns or if a power down of the full array is necessary due to the
presence of a marine mammal close to the vessel. Underwater sound
propagation of a 10-in\3\ airgun was measured near Harrison Bay in 2007
and results were reported in Funk et al. (2008). The 190 dB and 180 dB
distances from those measurements, 5 m and 20 m respectively, will be
used as the pre-sound source measurement safety zones during use of the
single mitigation gun.
An acoustics contractor will perform the direct measurements of the
received levels of underwater sound versus distance and direction from
the energy source arrays using calibrated hydrophones. The acoustic
data will be analyzed as quickly as reasonably practicable in the field
and used to verify (and if necessary adjust) the safety distances. The
mitigation measures to be implemented at the 190 and 180 dB sound
levels will include power downs and shut downs as described below.
(3) Power Downs and Shut Downs
A power-down is the immediate reduction in the number of operating
energy sources from all firing to some smaller number. A shutdown is
the immediate cessation of firing of all energy sources. The arrays
will be immediately powered down whenever a marine mammal is sighted
approaching close to or within the applicable safety zone of the full
arrays but is outside or about to enter the applicable safety zone of
the single mitigation source. If a marine mammal is sighted within the
applicable safety zone of the single mitigation airgun, the entire
array will be shut down (i.e., no sources firing). Although MMOs will
be located on the bridge ahead of the center of the airgun array, the
shutdown criterion for animals ahead of the vessel will be based on the
distance from the bridge (vantage point for MMOs) rather than from the
airgun array--a precautionary approach. For marine mammals sighted
alongside or behind the airgun array, the distance is measured from the
array.
Following a power-down or shutdown, operation of the airgun array
will not resume until the marine mammal has cleared the applicable
safety zone. The animal will be considered to have cleared the safety
zone if it:
[[Page 49749]]
Is visually observed to have left the safety zone;
Has not been seen within the zone for 15 min in the case
of small odontocetes and pinnipeds; or
Has not been seen within the zone for 30 min in the case
of mysticetes.
In the unanticipated event that an injured or dead marine mammal is
sighted within an area where Shell deployed and utilized seismic
airguns within the past 24 hours, Shell will immediately shutdown the
seismic airgun array and notify the Marine Mammal Stranding Network
within 24 hours of the sighting.
In the event that the marine mammal has been determined to have
been deceased for at least 72 hours, as certified by the lead MMO
onboard the source vessel, and no other marine mammals have been
reported injured or dead during that same 72 hour period, the airgun
array may be restarted (by conducting the necessary ramp-up procedures
described elsewhere in this section of the document) upon completion of
a written certification by the MMO. The certification must include the
following: species or description of the animal(s); the condition of
the animal(s) (including carcass condition if the animal is dead);
location and time of first discovery; observed behaviors (if alive);
and photographs or video (if available). Within 24 hours after the
event specified herein, Shell must notify NMFS by telephone or email of
the event and ensure that the written certification is provided to
NMFS.
In the event that the marine mammal injury resulted from something
other than seismic airgun operations (e.g., gunshot wound, polar bear
attack), as certified by the lead MMO onboard the seismic vessel, the
airgun array may be restarted (by conducting the necessary ramp-up
procedures described elsewhere in this section of the document) upon
completion of a written certification by the MMO. The certification
must include the following: species or description of the animal(s);
the condition of the animal(s) (including carcass condition if the
animal is dead); location and time of first discovery; observed
behaviors (if alive); and photographs or video (if available). Within
24 hours after the event specified herein, Shell must notify NMFS by
telephone or email of the event and ensure that the written
certification is provided to NMFS.
In the event the animal has not been dead for a period greater than
72 hours or the cause of the injury or death cannot be immediately
determined by the lead MMO, Shell shall immediately report the incident
to either the NMFS staff person designated by the Director, Office of
Protected Resources or to the staff person designated by the Alaska
Regional Administrator. The lead MMO must complete written
certification and provide it to the NMFS staff person. The
certification must include the following: species or description of the
animal(s); the condition of the animal(s) (including carcass condition
if the animal is dead); location and time of first discovery; observed
behaviors (if alive); and photographs or video (if available). The
airgun array may be restarted (by conducting the necessary ramp-up
procedures described elsewhere in this section of the document) upon
completion of the written certification.
In the event that the marine mammal death or injury was directly
caused by the seismic airgun operations (e.g., struck by a vessel,
entangled in gear), Shell shall immediately report the incident to the
designated NMFS staff person by telephone or email and the Marine
Mammal Stranding Network of the event and ensure that written
certification is provided to the NMFS staff person. The certification
must include the following: species or description of the animal(s);
the condition of the animal(s) (including carcass condition if the
animal is dead); location and time of first discovery; observed
behaviors (if alive); and photographs or video (if available). The
airguns may not be restarted until NMFS has had an opportunity to
review the written certification and any accompanying documentation,
make determinations as to whether modifications to the activities are
appropriate and necessary, and has notified Shell that activities may
be resumed. Approval to resume operations may be provided via letter,
e-mail, or telephone.
(4) Ramp Ups
A ramp up of an airgun array provides a gradual increase in sound
levels, and involves a stepwise increase in the number and total volume
of airguns firing until the full volume is achieved.
The purpose of a ramp up (or ``soft start'') is to ``warn''
cetaceans and pinnipeds in the vicinity of the airguns and to provide
time for them to leave the area and thus avoid any potential injury or
impairment of their hearing abilities.
During the proposed shallow hazards survey program, the seismic
operator will ramp up the airgun arrays slowly. Full ramp ups (i.e.,
from a cold start after a shut down, when no airguns have been firing)
will begin by firing a single airgun in the array. The minimum duration
of a shut-down period, i.e., without air guns firing, which must be
followed by a ramp up typically is the amount of time it would take the
source vessel to cover the 180-dB safety radius. The actual time period
depends on ship speed and the size of the 180-dB safety radius. That
period is estimated to be about 1-2 minutes based on the modeling
results described above and a survey speed of 4 knots.
A full ramp up, after a shut down, will not begin until there has
been a minimum of 30 min of observation of the safety zone by MMOs to
assure that no marine mammals are present. The entire safety zone must
be visible during the 30-minute lead-in to a full ramp up. If the
entire safety zone is not visible, then ramp up from a cold start
cannot begin. If a marine mammal(s) is sighted within the safety zone
during the 30-minute watch prior to ramp up, ramp up will be delayed
until the marine mammal(s) is sighted outside of the safety zone or the
animal(s) is not sighted for at least 15-30 minutes: 15 minutes for
small odontocetes and pinnipeds, or 30 minutes for baleen whales and
large odontocetes.
During turns and transit between seismic transects, at least one
airgun will remain operational. The ramp-up procedure still will be
followed when increasing the source levels from one airgun to the full
arrays. However, keeping one airgun firing will avoid the prohibition
of a cold start during darkness or other periods of poor visibility.
Through use of this approach, seismic operations can resume upon entry
to a new transect without a full ramp up and the associated 30-minute
lead-in observations. MMOs will be on duty whenever the airguns are
firing during daylight, and during the 30-min periods prior to ramp-ups
as well as during ramp-ups. Daylight will occur for 24 h/day until mid-
August, so until that date MMOs will automatically be observing during
the 30-minute period preceding a ramp up. Later in the season, MMOs
will be called out at night to observe prior to and during any ramp up.
The seismic operator and MMOs will maintain records of the times when
ramp-ups start, and when the airgun arrays reach full power.
To help evaluate the utility and effectiveness of ramp-up
procedures, MMOs are required to record and report their observations
during any ramp-up period.
(5) Mitigation Measures Concerning Bowhead Cow/Calf Pairs and Whale
Aggregations
For seismic activities (including shallow hazards and site
clearance and
[[Page 49750]]
other marine surveys where active acoustic sources will be employed) in
the Beaufort Sea after August 25, a 120-dB monitoring (safety) zone for
bowhead whales will be established and monitored for the next 24 hours
if four or more bowhead whale cow/calf pairs are observed at the
surface during an aerial monitoring program within the area where an
ensonified 120-dB zone around the vessel's track is projected. To the
extent practicable, such monitoring should focus on areas upstream
(eastward) of the bowhead migration. No seismic surveying shall occur
within the 120-dB safety zone around the area where these whale cow-
calf pairs were observed, until two consecutive surveys (aerial or
vessel) indicate they are no longer present within the 120-dB safety
zone of seismic-surveying operations.
A 160-dB vessel monitoring zone for bowhead and gray whales will be
established and monitored in the Chukchi Sea and after August 25 in the
Beaufort Sea during all seismic surveys. Whenever an aggregation of
bowhead whales or gray whales (12 or more whales of any age/sex class
that appear to be engaged in a nonmigratory, significant biological
behavior (e.g., feeding, socializing)) are observed during an aerial or
vessel monitoring program within the 160-dB safety zone around the
seismic activity, the seismic operation will not commence or will shut
down, until two consecutive surveys (aerial or vessel) indicate they
are no longer present within the 160-dB safety zone of seismic-
surveying operations.
Survey information, especially information about bowhead whale cow-
calf pairs or feeding bowhead or gray whale aggregations, shall be
provided to NMFS as required in MMPA authorizations, and will form the
basis for NMFS determining whether additional mitigation measures, if
any, will be required over a given time period.
(6) Mitigation Measures Concerning Vessel Speed and Directions
Furthermore, the following measures concerning vessel speed and
directions are required for Shell's 2010 open water marine survey
program in the Beaufort and Chukchi Seas:
All vessels should reduce speed to below 10 knots when
within 300 yards (274 m) of whales, and those vessels capable of
steering around such groups should do so. Vessels may not be operated
in such a way as to separate members of a group of whales from other
members of the group;
Avoid multiple changes in direction and speed when within
300 yards (274 m) of whales; and
When weather conditions require, such as when visibility
drops, support vessels must adjust speed accordingly to avoid the
likelihood of injury to whales.
(7) Subsistence Mitigation Measures
The following mitigation measures, plans, and programs shall be
implemented to reduce impacts from Shell's marine surveys that could
potentially affect subsistence groups and communities. These measures,
plans, and programs have been effective in past seasons of work in the
Arctic and were developed in past consultations with these communities.
These measures, plans, and programs will be implemented by Shell during
its 2010 program in both the Beaufort and Chukchi Seas to monitor and
mitigate potential impacts to subsistence users and resources.
Shell states that it will implement the following additional
measures to ensure coordination of its activities with local
subsistence users to minimize further the risk of impacting marine
mammals and interfering with any subsistence hunts:
For the purposes of reducing or eliminating conflicts
between subsistence whaling activities and Shell's survey program,
Shell will participate with other operators in the Communication and
Call Centers (Com-Center) Program. The Com-Centers will be operated 24
hours/day during the 2010 fall subsistence bowhead whale hunt.
To minimize impacts on marine mammals and subsistence
hunting activities, the source vessel will transit through the Chukchi
Sea along a route that lies offshore of the polynya zone. This entry
into the Chukchi Sea will not occur before July 1, 2010. In the event
the transit outside of the polynya zone results in Shell having to move
away from ice, the source vessel may enter into the polynya zone. If it
is necessary to move into the polynya zone, Shell will notify the local
communities of the change in the transit route through the Com-Centers.
Shell has developed a Communication Plan and will
implement the plan before initiating the 2010 program to coordinate
activities with local subsistence users as well as Village Whaling
Associations in order to minimize the risk of interfering with
subsistence hunting activities, and keep current as to the timing and
status of the bowhead whale migration, as well as the timing and status
of other subsistence hunts. The Communication Plan includes procedures
for coordination with Com-Centers to be located in coastal villages
along the Beaufort and Chukchi Seas during Shell's program in 2010.
Shell will employ local Subsistence Advisors from the
Beaufort and Chukchi Sea villages to provide consultation and guidance
regarding the whale migration and subsistence hunt. There may be up to
nine subsistence advisor-liaison positions (one per village), to work
approximately 8 hours per day and 40-hour weeks through Shell's 2010
program. The subsistence advisor will use local knowledge (Traditional
Knowledge) to gather data on subsistence lifestyle within the community
and advise as to ways to minimize and mitigate potential impacts to
subsistence resources during program activities. Responsibilities
include reporting any subsistence concerns or conflicts; coordinating
with subsistence users; reporting subsistence-related comments,
concerns, and information; and advising how to avoid subsistence
conflicts. A subsistence advisor handbook will be developed prior to
the operational season to specify position work tasks in more detail.
Shell will also implement flight restrictions prohibiting
aircraft from flying within 1,000 ft (300 m) of marine mammals or below
1,500 ft (457 m) altitude (except during takeoffs and landings or in
emergency situations) while over land or sea.
Upon notification by a Com-Center operator of an at-sea
emergency, Shell will provide such assistance as necessary to prevent
the loss of life, if conditions allow the holder of this Authorization
to safely do so.
Upon request for emergency assistance made by a
subsistence whale hunting organization, or by a member of such an
organization, in order to prevent the loss of a whale, the holder of
this Authorization shall assist towing of a whale taken in a
traditional subsistence whale hunt, if conditions allow Shell to safely
do so.
Post-season Review: Following completion of the 2010
Beaufort and Chukchi Seas open water marine survey program, Shell will
conduct a co-management meeting with the commissioners and committee
heads to discuss results of mitigation measures and outcomes of the
preceding season. The goal of the post-season meeting is to build upon
the knowledge base, discuss successful or unsuccessful outcomes of
mitigation measures, and possibly refine plans or mitigation measures
if necessary.
[[Page 49751]]
Mitigation Conclusions
NMFS has carefully evaluated the applicant's proposed mitigation
measures and considered a range of other measures in the context of
ensuring that NMFS prescribes the means of effecting the least
practicable impact on the affected marine mammal species and stocks and
their habitat. Our evaluation of potential measures included
consideration of the following factors in relation to one another:
The manner in which, and the degree to which, the
successful implementation of the measure is expected to minimize
adverse impacts to marine mammals;
The proven or likely efficacy of the specific measure to
minimize adverse impacts as planned; and
The practicability of the measure for applicant
implementation.
Based on our evaluations and analyses of the aforementioned
mitigation measures, NMFS has determined that the mitigation measures
provide the means of effecting the least practicable impact on marine
mammal species or stocks and their habitat, paying particular attention
to rookeries, mating grounds, and areas of similar significance, and
will have no unmitigable impact to subsistence hunt.
Monitoring and Reporting Measures
In order to issue an ITA for an activity, Section 101(a)(5)(D) of
the MMPA states that NMFS must, where applicable, set forth
``requirements pertaining to the monitoring and reporting of such
taking.'' The MMPA implementing regulations at 50 CFR 216.104 (a)(13)
indicate that requests for ITAs must include the suggested means of
accomplishing the necessary monitoring and reporting that will result
in increased knowledge of the species and of the level of taking or
impacts on populations of marine mammals that are expected to be
present in the proposed action area.
Monitoring Measures
The following monitoring measures are required for Shell's 2010
open water marine survey program in the Beaufort and Chukchi Seas.
(1) Vessel-based MMOs
Vessel-based monitoring for marine mammals will be done by trained
MMOs throughout the period of marine survey activities. MMOs will
monitor the occurrence and behavior of marine mammals near the survey
vessel during all daylight periods during operation and during most
daylight periods when airgun operations are not occurring. MMO duties
will include watching for and identifying marine mammals, recording
their numbers, distances, and reactions to the survey operations, and
documenting ``take by harassment'' as defined by NMFS.
A sufficient number of MMOs will be required onboard the survey
vessel to meet the following criteria: (1) 100% monitoring coverage
during all periods of survey operations in daylight; (2) maximum of 4
consecutive hours on watch per MMO; and (3) maximum of 12 hours of
watch time per day per MMO.
MMO teams will consist of Inupiat observers and experienced field
biologists. An experienced field crew leader will supervise the MMO
team onboard the survey vessel. New observers shall be paired with
experienced observers to avoid situations where lack of experience
impairs the quality of observations. The total number of MMOs may
decrease later in the season as the duration of daylight decreases.
Shell anticipates that there will be provision for crew rotation at
least every six to eight weeks to avoid observer fatigue. During crew
rotations detailed hand-over notes will be provided to the incoming
crew leader by the outgoing leader. Other communications such as email,
fax, and/or phone communication between the current and oncoming crew
leaders during each rotation will also occur when possible. In the
event of an unexpected crew change Shell will facilitate such
communications to insure monitoring consistency among shifts.
Crew leaders and most other biologists serving as observers in 2010
will be individuals with experience as observers during one or more of
the 1996-2009 seismic or shallow hazards monitoring projects in Alaska,
the Canadian Beaufort, or other offshore areas in recent years.
Biologist-observers will have previous marine mammal observation
experience, and field crew leaders will be highly experienced with
previous vessel-based marine mammal monitoring and mitigation projects.
Resumes for those individuals will be provided to NMFS for review and
acceptance of their qualifications. Inupiat observers will be
experienced in the region, familiar with the marine mammals of the
area, and complete a NMFS-approved observer training course designed to
familiarize individuals with monitoring and data collection procedures.
A marine mammal observers' handbook, adapted for the specifics of the
planned survey program, will be prepared and distributed beforehand to
all MMOs.
Most observers, including Inupiat observers, will also complete a
two-day training and refresher session on marine mammal monitoring, to
be conducted shortly before the anticipated start of the 2010 open-
water season. Any exceptions will have or receive equivalent experience
or training. The training session(s) will be conducted by qualified
marine mammalogists with extensive crew-leader experience during
previous vessel-based seismic monitoring programs. Observers should be
trained using visual aids (e.g., videos, photos), to help them identify
the species that they are likely to encounter in the conditions under
which the animals will likely be seen.
If there are Alaska Native MMOs, the MMO training that is conducted
prior to the start of the survey activities should be conducted with
both Alaska Native MMOs and biologist MMOs being trained at the same
time in the same room. There should not be separate training courses
for the different MMOs.
Primary objectives of the training include:
Review of the marine mammal monitoring plan for this
project, including any amendments specified by NMFS in the IHA (if
issued), by USFWS and by MMS, or by other agreements in which Shell may
elect to participate;
Review of marine mammal sighting, identification, and
distance estimation methods;
Review of operation of specialized equipment (reticle
binoculars, night vision devices, and GPS system);
Review of, and classroom practice with, data recording and
data entry systems, including procedures for recording data on marine
mammal sightings, monitoring operations, environmental conditions, and
entry error control. These procedures will be implemented through use
of a customized computer database and laptop computers; and
Review of the specific tasks of the Inupiat Communicator.
Observers should understand the importance of classifying marine
mammals as ``unknown'' or ``unidentified'' if they cannot identify the
animals to species with confidence. In those cases, they should note
any information that might aid in the identification of the marine
mammal sighted. For example, for an unidentified mysticete whale, the
observers should record whether the animal had a dorsal fin.
MMOs will watch for marine mammals from the best available vantage
point on the survey vessel, typically the bridge. MMOs will scan
systematically with the unaided eye and
[[Page 49752]]
7 x 50 reticle binoculars, supplemented with 20 x 60 image-stabilized
Zeiss Binoculars or Fujinon 25 x 150 ``Big-eye'' binoculars and night-
vision equipment when needed. With two or three observers on watch, the
use of big eyes should be paired with searching by naked eye, the
latter allowing visual coverage of nearby areas to detect marine
mammals. Personnel on the bridge will assist the MMOs in watching for
marine mammals.
Observers should attempt to maximize the time spent looking at the
water and guarding the safety radii. They should avoid the tendency to
spend too much time evaluating animal behavior or entering data on
forms, both of which detract from their primary purpose of monitoring
the safety zone.
Observers should use the best possible positions for observing
(e.g., outside and as high on the vessel as possible), taking into
account weather and other working conditions. MMOs shall carefully
document visibility during observation periods so that total estimates
of take can be corrected accordingly.
Information to be recorded by marine mammal observers will include
the same types of information that were recorded during recent
monitoring programs associated with Industry activity in the Arctic
(e.g., Ireland et al. 2009). When a mammal sighting is made, the
following information about the sighting will be recorded:
(A) Species, group size, age/size/sex categories (if determinable),
behavior when first sighted and after initial sighting, heading (if
consistent), bearing and distance from the MMO, apparent reaction to
activities (e.g., none, avoidance, approach, paralleling, etc.),
closest point of approach, and behavioral pace;
(B) Time, location, speed, activity of the vessel, sea state, ice
cover, visibility, and sun glare;
(C) The positions of other vessel(s) in the vicinity of the MMO
location; and
(D) Whether adjustments were made to Shell's activity status.
The ship's position, speed of support vessels, and water
temperature, water depth, sea state, ice cover, visibility, and sun
glare will also be recorded at the start and end of each observation
watch, every 30 minutes during a watch, and whenever there is a change
in any of those variables.
Distances to nearby marine mammals will be estimated with
binoculars (Fujinon 7 x 50 binoculars) containing a reticle to measure
the vertical angle of the line of sight to the animal relative to the
horizon. MMOs may use a laser rangefinder to test and improve their
abilities for visually estimating distances to objects in the water.
However, previous experience showed that a Class 1 eye-safe device was
not able to measure distances to seals more than about 230 ft (70 m)
away. The device was very useful in improving the distance estimation
abilities of the observers at distances up to about 1,968 ft (600 m)--
the maximum range at which the device could measure distances to highly
reflective objects such as other vessels. Humans observing objects of
more-or-less known size via a standard observation protocol, in this
case from a standard height above water, quickly become able to
estimate distances within about 20% when given immediate
feedback about actual distances during training.
For monitoring related to deployment of the AUV, MMOs will advise
the vehicle operators prior to deployment if aggregations of marine
mammals have been observed in the survey area which might increase the
likelihood of the vehicle encountering an animal or otherwise
disturbing a group of animals.
Shell plans to conduct the site clearance and shallow hazards
survey 24 hr/day. Regarding nighttime operations, note that there will
be no periods of total darkness until mid-August. When operating under
conditions of reduced visibility attributable to darkness or to adverse
weather conditions, night-vision equipment (``Generation 3'' binocular
image intensifiers, or equivalent units) will be available for use.
(2) Aerial Survey Program
Shell proposes to conduct an aerial survey program in support of
the shallow hazards program in the Beaufort Sea during the fall of
2010. The shallow hazards survey program may start in the Beaufort Sea
as early as July 2010, however, aerial surveys would not begin until
the start of the bowhead whale migration, around August 20, 2010. The
objectives of the aerial survey will be:
To advise operating vessels as to the presence of marine
mammals (primarily cetaceans) in the general area of operation;
To collect and report data on the distribution, numbers,
movement and behavior of marine mammals near the survey operations with
special emphasis on migrating bowhead whales;
To support regulatory reporting related to the estimation
of impacts of survey operations on marine mammals;
To investigate potential deflection of bowhead whales
during migration by documenting how far east of survey operations a
deflection may occur and where whales return to normal migration
patterns west of the operations; and
To monitor the accessibility of bowhead whales to Inupiat
hunters.
Specially-outfitted Twin Otter aircraft have an excellent safety
record and are expected to be the survey aircraft. These aircraft will
be specially modified for survey work and have been used extensively by
NMFS, Alaska Department of Fish and Game, North Slope Borough, and LGL
Limited during many marine mammal projects in Alaska, including
industry-funded projects as recent as the 2006-2008 seasons. The
aircraft will be provided with a comprehensive set of survival
equipment appropriate to offshore surveys in the Arctic. For safety
reasons, the aircraft will be operated with two pilots.
Aerial survey flights will begin around August 20, 2010. Surveys
will then be flown daily during the shallow hazards survey operations,
weather and flight conditions permitting, and continued for 5 to 7 days
after all activities at the site have ended.
The aerial survey procedures will be generally consistent with
those used during earlier industry studies (Davis et al. 1985; Johnson
et al. 1986; Evans et al. 1987; Miller et al. 1997, 1998, 1999, 2002;
Patterson 2007). This will facilitate comparison and pooling of data
where appropriate. However, the specific survey grids will be tailored
to Shell's operations. During the 2010 open-water season Shell will
coordinate and cooperate with the aerial surveys conducted by MMS/NMFS
and any other groups conducting surveys in the same region.
It is understood that shallow hazard survey timing and the specific
location offshore of Harrison Bay are subject to change as a result of
unpredictable weather and ice conditions. The aerial survey design is
therefore intended to be flexible and able to adapt at short notice to
changes in the operations.
For marine mammal monitoring flights, aircraft will be flown at
approximately 120 knots (138 mph) ground speed and usually at an
altitude of 1,000 ft (305 m). Flying at a survey speed of 120 knots
(138 mph) greatly increases the amount of area that can be surveyed,
given aircraft limitations, with minimal effect on the ability to
detect bowhead whales. Surveys in the Beaufort Sea are directed at
bowhead whales, and an altitude of 900-1,000 ft (274-305 m) is the
lowest survey altitude that can normally be flown without concern about
potential aircraft disturbance. Aerial surveys at an altitude of 1,000
ft (305 m) do not provide much information about seals
[[Page 49753]]
but are suitable for both bowhead and beluga whales. The need for a
900-1,000+ (374-305 m) ft cloud ceiling will limit the dates and times
when surveys can be flown.
Two primary observers will be seated at bubble windows on either
side of the aircraft and a third observer will observe part time and
record data the rest of the time. All observers need bubble windows to
facilitate downward viewing. For each marine mammal sighting, the
observer will dictate the species, number, size/age/sex class when
determinable, activity, heading, swimming speed category (if
traveling), sighting cue, ice conditions (type and percentage), and
inclinometer reading to the marine mammal into a digital recorder. The
inclinometer reading will be taken when the animal's location is
90[deg] to the side of the aircraft track, allowing calculation of
lateral distance from the aircraft trackline.
Transect information, sighting data and environmental data will be
entered into a GPS-linked computer by the third observer and
simultaneously recorded on digital voice recorders for backup and
validation. At the start of each transect, the observer recording data
will record the transect start time and position, ceiling height (ft),
cloud cover (in 10ths), wind speed (knots), wind direction ([deg]T) and
outside air temperature ([deg]C). In addition, each observer will
record the time, visibility (subjectively classified as excellent,
good, moderately impaired, seriously impaired or impossible), sea state
(Beaufort wind force), ice cover (in 10ths) and sun glare (none,
moderate, severe) at the start and end of each transect, and at 2-min
intervals along the transect. This will provide data in units suitable
for statistical summaries and analyses of effects of these variables
(and position relative to the survey vessel) on the probability of
detecting animals (see Davis et al. 1982; Miller et al. 1999; Thomas et
al. 2002). The data logger will automatically record time and aircraft
position (latitude and longitude) for sightings and transect waypoints,
and at pre-selected intervals along transects.
Ice observations during aerial surveys will be recorded and
satellite imagery may be used, where available, during post-season
analysis to determine ice conditions adjacent to the survey area. These
are standard practices for surveys of this type and are necessary in
order to interpret factors responsible for variations in sighting
rates.
Shell will assemble the information needed to relate marine mammal
observations to the locations of the survey vessel, and to the
estimated received levels of industrial sounds at mammal locations.
During the aerial surveys, Shell will record relevant information on
other industry vessels, whaling vessels, low-flying aircraft, or any
other human activities that are observed in the survey area.
Shell will also consult with MMS/National Marine Mammal Laboratory
regarding coordination during the survey activities and real-time
sharing of data. The aims will be:
To ensure aircraft separation when both crews conduct
surveys in the same general region;
To coordinate the 2010 aerial survey projects in order to
maximize consistency and minimize duplication;
To use data from MMS's broad-scale surveys to supplement
the results of the more site specific Shell surveys for purposes of
assessing the effects of shallow hazard survey activities on whales and
estimating ``take by harassment'';
To maximize consistency with previous years' efforts
insofar as feasible.
It is expected that raw bowhead sighting and flight-line data will
be exchanged between MMS and Shell on a daily basis during the survey
period, and that each team will also submit its sighting information to
NMFS in Anchorage each day. After the Shell and MMS data files have
been reviewed and finalized, they will be exchanged in digital form.
Shell is not aware of any other related aerial survey programs
presently scheduled to occur in the Alaskan Beaufort Sea in areas where
Shell is anticipated to be conducting survey operations during July-
October 2010. However, one or more other programs are possible in
support of other industry and research operations. If another aerial
survey project were planned, Shell would seek to coordinate with that
project to ensure aircraft separation, maximize consistency, minimize
duplication, and share data.
During the late summer and fall, bowhead whale is the primary
species of concern, but belugas and gray whales are also present. To
address concerns regarding deflection of bowheads at greater distances,
the survey pattern around shallow hazards survey operations has been
designed to document whale distribution from about 25 mi (40 km) east
of Shell's vessel operations to about 37 mi (60 km) west of operations
(see Figure 1 of Shell's 4MP).
Bowhead whale movements during the late summer/autumn are generally
from east to west, and transects should be designed to intercept rather
than parallel whale movements. The transect lines in the grid will be
oriented north-south, equally spaced at 5 mi (8 km) and randomly
shifted in the east-west direction for each survey by no more than the
transect spacing. The survey grid will total about 808 mi (1,300 km) in
length, requiring approximately 6 hours to survey at a speed of 120
knots (138 mph), plus ferry time. Exact lengths and durations will vary
somewhat depending on the position of the survey operation and thus of
the grid, the sequence in which lines are flown (often affected by
weather), and the number of refueling/rest stops.
Weather permitting, transects making up the grid in the Beaufort
Sea will be flown in sequence from west to east. This decreases
difficulties associated with double counting of whales that are
(predominantly) migrating westward.
(3) Acoustic Monitoring
As discussed earlier in this document, Shell will conduct SSV tests
to establish the isopleths for the applicable safety radii. In
addition, Shell proposes to use acoustic recorders to study bowhead
deflections.
Shell plans to deploy arrays of acoustic recorders in the Beaufort
Sea in 2010, similar to that which was done in 2007 and 2008 using
Directional Autonomous Seafloor Acoustic Recorders (DASARs) supplied by
Greeneridge. These directional acoustic systems permit localization of
bowhead whale and other marine mammal vocalizations. The purpose of the
array will be to further understand, define, and document sound
characteristics and propagation resulting from shallow hazards surveys
that may have the potential to cause deflections of bowhead whales from
their migratory pathway. Of particular interest will be the east-west
extent of deflection, if any (i.e., how far east of a sound source do
bowheads begin to deflect and how far to the west beyond the sound
source does deflection persist). Of additional interest will be the
extent of offshore (or towards shore) deflection that might occur.
In previous work around seismic operations in the Alaskan Beaufort
Sea, the primary method for studying this question has been aerial
surveys. Acoustic localization methods will provide supplementary
information for addressing the whale deflection question. Compared to
aerial surveys, acoustic methods have the advantage of providing a
vastly larger number of whale detections, and can operate day or night,
independent of visibility, and to some degree independent of ice
conditions and sea state--all of which
[[Page 49754]]
prevent or impair aerial surveys. However, acoustic methods depend on
the animals to call, and to some extent, assume that calling rate is
unaffected by exposure to industrial noise. Bowheads call frequently in
fall, but there is some evidence that their calling rate may be reduced
upon exposure to industrial sounds, complicating interpretation. The
combined use of acoustic and aerial survey methods will provide a suite
of information that should be useful in assessing the potential effects
of survey operations on migrating bowhead whales.
Using passive acoustics with directional autonomous recorders, the
locations of calling whales will be observed for a 6- to 10-week
continuous monitoring period at five coastal sites (subject to
favorable ice and weather conditions).
Shell plans to conduct the whale migration monitoring using the
passive acoustics techniques developed and used successfully since 2001
for monitoring the migration past Northstar production island northwest
of Prudhoe Bay and from Kaktovik to Harrison Bay during the 2007-2009
migrations. Those techniques involve using DASARs to measure the
arrival angles of bowhead calls at known locations, then triangulating
to locate the calling whale.
In attempting to assess the responses of bowhead whales to the
planned industrial operations, it will be essential to monitor whale
locations at sites both near and far from industry activities. Shell
plans to monitor at five sites along the Alaskan Beaufort coast as
shown in Figure 3 of Shell's 4MP. The eastern-most site (5 in
Figure 3 of the 4MP) will be just east of Kaktovik and the western-most
site (1 in Figure 3 of the 4MP) will be in the vicinity of
Harrison Bay. Site 2 will be located west of Prudhoe Bay. Sites 4 and 3
will be west of Camden Bay. These five sites will provide information
on possible migration deflection well in advance of whales encountering
an industry operation and on ``recovery'' after passing such operations
should a deflection occur.
The proposed geometry of DASARs at each site is comprised of seven
DASARs oriented in a north-south pattern resulting in five equilateral
triangles with 4.3-mi (7-km) element spacing. DASARs will be installed
at planned locations using a GPS. However, each DASAR's orientation
once it settles on the bottom is unknown and must be determined to know
how to reference the call angles measured to the whales. Also, the
internal clocks used to sample the acoustic data typically drift
slightly, but linearly, by an amount up to a few seconds after 6 weeks
of autonomous operation. Knowing the time differences within a second
or two between DASARs is essential for identifying identical whale
calls received on two or more DASARs.
Bowhead migration begins in late August with the whales moving
westward from their feeding sites in the Canadian Beaufort Sea. It
continues through September and well into October. Shell will attempt
to install the 21 DASARs at three sites (3, 4 and 5) in early August.
The remaining 14 DASARs will be installed at sites 1 and 2 in late
August. Thus, Shell proposes monitoring for whale calls from before
August 15 until sometime before October 15, 2010.
At the end of the season, the fourth DASAR in each array will be
refurbished, recalibrated, and redeployed to collect data through the
winter. The other DASARs in the arrays will be recovered. The
redeployed DASARs will be programmed to record 35 min every 3 hours
with a disk capacity of 10 months at that recording rate. This should
be ample space to allow over-wintering from approximately mid-October
2010, through mid-July 2011.
Additional details on methodology and data analysis for the three
types of monitoring described here (i.e., vessel-based, aerial, and
acoustic) can be found in the 4MP in Shell's application (see
ADDRESSES).
Reporting Measures
(1) SSV Report
A report on the preliminary results of the acoustic verification
measurements, including as a minimum the measured 190-, 180-, 160-, and
120-dB re 1 [mu]Pa (rms) radii of the source vessel(s) and the support
vessels, will be submitted within 120 hr after collection and analysis
of those measurements at the start of the field season. This report
will specify the distances of the safety zones that were adopted for
the marine survey activities.
(2) Technical Reports
The results of Shell's 2010 open water marine survey monitoring
program (i.e., vessel-based, aerial, and acoustic), including estimates
of ``take'' by harassment, will be presented in the ``90-day'' and
Final Technical reports. The Technical Reports will include: (a)
Summaries of monitoring effort (e.g., total hours, total distances, and
marine mammal distribution through the study period, accounting for sea
state and other factors affecting visibility and detectability of
marine mammals); (b) analyses of the effects of various factors
influencing detectability of marine mammals (e.g., sea state, number of
observers, and fog/glare); (c) species composition, occurrence, and
distribution of marine mammal sightings, including date, water depth,
numbers, age/size/gender categories (if determinable), group sizes, and
ice cover; (d) analyses of the effects of survey operations; (e)
sighting rates of marine mammals during periods with and without airgun
activities (and other variables that could affect detectability); (f)
initial sighting distances versus airgun activity state; (g) closest
point of approach versus airgun activity state; (h) observed behaviors
and types of movements versus airgun activity state; (i) numbers of
sightings/individuals seen versus airgun activity state; (j)
distribution around the survey vessel versus airgun activity state; and
(k) estimates of take by harassment. This information will be reported
for both the vessel-based and aerial monitoring. In addition, Shell
shall provide all spatial data on charts (always including vessel
location) and make all data available in the report, preferably
electronically, for integration with data from other companies. Shell
shall also accommodate specific requests for raw data, including tracks
of all vessels and aircraft associated with the operation and activity
logs documenting when and what types of sounds are introduced into the
environment by the operation.
Analysis of all acoustic data will be prioritized to address the
primary questions. The primary data analysis questions are to (a)
Determine when, where, and what species of animals are acoustically
detected on each DASAR, (b) analyze data as a whole to determine
offshore bowhead distributions as a function of time, (c) quantify
spatial and temporal variability in the ambient noise, and (d) measure
received levels of airgun activities. The bowhead detection data will
be used to develop spatial and temporal animal distributions.
Statistical analyses will be used to test for changes in animal
detections and distributions as a function of different variables
(e.g., time of day, time of season, environmental conditions, ambient
noise, vessel type, operation conditions).
The initial technical report is due to NMFS within 90 days of the
completion of Shell's Beaufort and Chukchi Seas open water marine
survey programs. The ``90-day'' report will be subject to review and
comment by NMFS. Any recommendations made by NMFS must be addressed in
the final report prior to acceptance by NMFS.
[[Page 49755]]
(3) Comprehensive Report
In November, 2007, Shell (in coordination and cooperation with
other Arctic seismic IHA holders) released a final, peer-reviewed
edition of the 2006 Joint Monitoring Program in the Chukchi and
Beaufort Seas, July-November 2006 (LGL 2007). This report is available
on the NMFS Protected Resources Web site (see ADDRESSES). In March,
2009, Shell released a final, peer-reviewed edition of the Joint
Monitoring Program in the Chukchi and Beaufort Seas, Open Water
Seasons, 2006-2007 (Ireland et al. 2009). This report is also available
on the NMFS Protected Resources Web site (see ADDRESSES). A draft
comprehensive report for 2008 (Funk et al. 2009) was provided to NMFS
and those attending the Arctic Stakeholder Open-water Workshop in
Anchorage, Alaska, on April 6-8, 2009. The 2008 report provides data
and analyses from a number of industry monitoring and research studies
carried out in the Chukchi and Beaufort Seas during the 2008 open-water
season with comparison to data collected in 2006 and 2007. Reviewers
plan to provide comments on the 2008 report to Shell shortly. Once
Shell is able to incorporate reviewer comments, the final 2008 report
will be made available to the public. The 2009 draft comprehensive
report is due to NMFS by mid-April 2010. NMFS will make this report
available to the public upon receipt.
Following the 2010 shallow hazards surveys a comprehensive report
describing the vessel-based, aerial, and acoustic monitoring programs
will be prepared. The comprehensive report will describe the methods,
results, conclusions and limitations of each of the individual data
sets in detail. The report will also integrate (to the extent possible)
the studies into a broad based assessment of industry activities, and
other activities that occur in the Beaufort and/or Chukchi seas, and
their impacts on marine mammals during 2010. The report will help to
establish long-term data sets that can assist with the evaluation of
changes in the Chukchi and Beaufort Seas ecosystems. The report will
attempt to provide a regional synthesis of available data on industry
activity in offshore areas of northern Alaska that may influence marine
mammal density, distribution and behavior. The comprehensive report
will be due to NMFS within 240 days of the date of issuance of the IHA
(if issued).
(4) Notification of Injured or Dead Marine Mammals
Shell will notify NMFS' Office of Protected Resources and NMFS'
Stranding Network within 48 hours of sighting an injured or dead marine
mammal in the vicinity of marine survey operations. Shell will provide
NMFS with the species or description of the animal(s), the condition of
the animal(s) (including carcass condition if the animal is dead),
location, time of first discovery, observed behaviors (if alive), and
photo or video (if available).
In the event that an injured or dead marine mammal is found by
Shell that is not in the vicinity of the proposed open water marine
survey program, Shell will report the same information as listed above
as soon as operationally feasible to NMFS.
Negligible Impact and Small Numbers Analysis and Determination
NMFS has defined ``negligible impact'' in 50 CFR 216.103 as ``* * *
an impact resulting from the specified activity that cannot be
reasonably expected to, and is not reasonably likely to, adversely
affect the species or stock through effects on annual rates of
recruitment or survival.'' In making a negligible impact determination,
NMFS considers a variety of factors, including but not limited to: (1)
The number of anticipated mortalities; (2) the number and nature of
anticipated injuries; (3) the number, nature, intensity, and duration
of Level B harassment; and (4) the context in which the takes occur.
No injuries or mortalities are anticipated to occur as a result of
Shell's proposed 2010 open water marine surveys in the Beaufort and
Chukchi Seas, and none are proposed to be authorized. Additionally, as
discussed previously in this document, animals in the area are not
expected to incur hearing impairment (i.e., TTS or PTS) or non-auditory
physiological effects. Takes will be limited to Level B behavioral
harassment. Although it is possible that some individuals of marine
mammals may be exposed to sounds from marine survey activities more
than once, the expanse of these multi-exposures are expected to be less
extensive since both the animals and the survey vessels will be moving
constantly in and out the survey areas.
The proposed marine survey areas in the Beaufort and Chukchi Seas
are not known habitat for breeding or calving for marine mammals during
the time of the proposed marine survey activities.
Although bowhead whales are observed feeding in the Beaufort and
Chukchi Seas during the summer, some studies have shown that bowhead
whales will continue to feed in areas of seismic operations (e.g.,
Richardson et al. 2004). Therefore, it is reasonable to conclude that
the marine surveys using active acoustic sources will not displace
bowhead whales from their important feeding areas. Also, it is
important to note that the sounds produced by the proposed Shell marine
surveys are of much lower intensity than those produced by airgun
arrays during a 3D or 2D seismic survey. Should bowheads choose to feed
in the ensonified area instead of avoiding the sound, individuals may
be exposed to sounds at or above 160 dB re 1 [mu]Pa (rms) when the
survey vessel passes by. Depending on the direction and speed of the
survey vessel, the duration of exposure is not expected to be more than
15 minutes (assuming the survey vessel is traveling at 4 knots (7.5 km/
hr) and heading directly towards the whale but without engaging the
whale inside the safety zone). While feeding in an area of increased
anthropogenic sound even below NMFS current threshold for behavioral
harassment for impulse sound, i.e. 160 dB re 1 [mu]Pa (rms), may
potentially result in increased stress, it is not anticipated that the
low received levels from marine surveys and the amount of time that an
individual whale may remain in the area to feed would result in extreme
physiological stress to the animal (see review by Southall et al.
2007). Additionally, if an animal is excluded from the area (such as
Harrison Bay) for feeding because it decides to avoid the ensonified
area, this may result in some extra energy expenditure for the animal
to find an alternate feeding area. However, there are multiple feeding
areas nearby in the Beaufort Sea for bowhead whales to choose from. The
disruption to feeding is not anticipated to have more than a negligible
impact on the affected species or stock.
Beluga whales are less likely to occur in the proposed marine
survey area than bowhead whales in Beaufort Sea. Should any belugas
occur in the area of marine surveys, it is not expected that they would
be exposed for a prolonged period of time, for the same reason
discussed above due to the movement of survey vessel and animals. Gray
whales, humpback whales, and harbor porpoises rarely occur in the
Beaufort Sea, therefore, the potential effects to these species from
the proposed open water marine surveys is expected to be close to none.
The exposure of cetaceans to sounds produced by the proposed marine
surveys is not expected to result in more than Level B harassment and
is
[[Page 49756]]
anticipated to have no more than a negligible impact on the affected
species or stock.
Some individual pinnipeds may be exposed to sound from the proposed
marine surveys more than once during the time frame of the project.
However, as discussed previously, due to the constant moving of the
survey vessel, the probability of an individual pinniped being exposed
to sound multiple times is much lower than if the source is stationary.
Therefore, NMFS has determined that the exposure of pinnipeds to sounds
produced by the proposed marine surveys in the Beaufort and Chukchi
Seas is not expected to result in more than Level B harassment and is
anticipated to have no more than a negligible impact on the affected
species or stock.
Of the eight marine mammal species likely to occur in the proposed
marine survey area, only the bowhead and humpback whales are listed as
endangered under the ESA. The species are also designated as
``depleted'' under the MMPA. Despite these designations, the Bering-
Chukchi-Beaufort stock of bowheads has been increasing at a rate of 3.4
percent annually for nearly a decade (Allen and Angliss 2010).
Additionally, during the 2001 census, 121 calves were counted, which
was the highest yet recorded. The calf count provides corroborating
evidence for a healthy and increasing population (Allen and Angliss
2010). The occurrence of humpback whales in the proposed marine survey
areas is considered very rare. There is no critical habitat designated
in the U.S. Arctic for the bowhead whale and humpback whale. The
bearded and ringed seals are ``candidate species'' under the ESA,
meaning they are currently being considered for listing but are not
designated as depleted under the MMPA. None of the other three species
that may occur in the project area are listed as threatened or
endangered under the ESA or designated as depleted under the MMPA.
Potential impacts to marine mammal habitat were discussed
previously in this document (see the ``Anticipated Effects on Habitat''
section). Although some disturbance is possible to food sources of
marine mammals, the impacts are anticipated to be minor enough as to
not affect rates of recruitment or survival of marine mammals in the
area. Based on the vast size of the Arctic Ocean where feeding by
marine mammals occurs versus the localized area of the marine survey
activities, any missed feeding opportunities in the direct project area
would be minor based on the fact that other feeding areas exist
elsewhere.
The estimated takes proposed to be authorized represent 0.01% of
the Beaufort Sea population of approximately 39,258 beluga whales
(Allen and Angliss 2010), 0.004% of Bering Sea stock of approximately
48,215 harbor porpoises, 0.01% of the Eastern North Pacific stock of
approximately 17,752 gray whales, 2.67% of the Bering-Chukchi-Beaufort
population of 14,247 individuals assuming 3.4 percent annual population
growth from the 2001 estimate of 10,545 animals (Zeh and Punt, 2005),
and 0.21% of the Western North Pacific stock of approximately 938
humpback whales. The take estimates presented for bearded, ringed, and
spotted seals represent 0.003, 0.06, and 0.002 percent of U.S. Arctic
stocks of each species, respectively. These estimates represent the
percentage of each species or stock that could be taken by Level B
behavioral harassment if each animal is taken only once. In addition,
the mitigation and monitoring measures (described previously in this
document) proposed for inclusion in the IHA (if issued) are expected to
reduce even further any potential disturbance to marine mammals.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the mitigation and monitoring
measures, NMFS finds that Shell's proposed 2010 open water marine
surveys in the Beaufort and Chukchi Seas may result in the incidental
take of small numbers of marine mammals, by Level B harassment only,
and that the total taking from the marine surveys will have a
negligible impact on the affected species or stocks.
Unmitigable Adverse Impact Analysis and Determination
NMFS has determined that Shell's proposed 2010 open water marine
surveys in the Beaufort and Chukchi Seas will not have an unmitigable
adverse impact on the availability of species or stocks for taking for
subsistence uses. This determination is supported by information
contained in this document and Shell's POC. Shell has adopted a spatial
and temporal strategy for its Arctic open water marine surveys that
should minimize impacts to subsistence hunters, which is discussed in
detail below, broken into different subsistence activities.
(1) Bowhead Whales
During the proposed period of activity (July through October) most
marine mammals are expected to be dispersed throughout the area, except
during the peak of the bowhead whale migration in the Beaufort Sea,
which occurs from late August into October. Bowhead whales are expected
to be in the Canadian Beaufort Sea during much of the time prior to
subsistence whaling and, therefore, are not expected to be affected by
the site clearance and shallow hazard surveys prior to then. Further,
site clearance and shallow hazards surveys will be conducted over 50-
100 mi (80-160 km) west of the furthest west boundary of the
traditional bowhead hunting waters used by Kaktovik hunters, 10-50 mi
(16-80 km) west of Cross Island from where Nuiqsut hunters base their
harvest, and over 35 miles east of the furthest east boundary of the
traditional bowhead hunting waters used by Barrow hunters. In light of
the small sound source for these surveys and resulting ensonified area
> 160 dB (1,525 m) described previously in this document, the sheer
distances from where these site clearance and shallow hazard surveys
will occur from the areas of Kaktovik and Barrow bowhead hunts serve to
mitigate any prospect of impact to the hunts. Site clearance and
shallow hazard surveys will be timed to occur beyond the traditional
boundary of Nuiqsut hunts, besides occurring 10-50 mi (16-80 km) west
of Cross Island and ``downstream'' of this bowhead whale hunt, thereby
mitigating the prospect of impact to Nuiqsut whaling. In addition,
Shell will execute a communication plan and use communication and call
centers located in coastal villages of the Beaufort Sea (see above) to
communicate activities and routine vessel traffic with subsistence
users throughout the period in which all surveys will be conducted. As
a result of the distance and spatial location of site clearance and
shallow hazard surveys from traditional bowhead whale subsistence
harvest, any effects on the bowhead whale, as a subsistence resource,
will be negligible.
Activities associated with Shell's planned ice gouge surveys in
Camden Bay would have no or negligible effect on the availability of
bowhead whales for the Kaktovik, Nuiqsut, and Barrow subsistence
whaling harvests. Mitigation of the impact from ice gouge surveys
includes the possible use of either an AUV, or conventional survey
method without airguns, and timing and location of surveys. The AUV
will be launched from the stern of a vessel and will survey the
seafloor close to the
[[Page 49757]]
vessel. The vessel will transit an area, with the AUV surveying the
area behind the vessel. Marine mammal observers onboard the vessel will
help to ensure the AUV has a minimal impact on the environment. The AUV
also has a Collision Avoidance System and operates without a towline,
thereby reducing potential impact to marine mammals. Using bathymetric
sonar or multi-beam echo sounder the AUV can record the gouges on the
seafloor surface caused by ice keels. The Sub-bottom profiler can
record layers beneath the surface to about 20 ft (6.1 m). The AUV is
more maneuverable and able to complete surveys more quickly than a
conventional survey. This reduces the duration that vessels producing
sound must operate. Also, the ice gouge surveys will be timed to avoid
locations east of Mary Sachs Entrance in Camden Bay during the bowhead
subsistence harvest of Kaktovik. The ice gouge survey locations through
Mary Sachs Entrance and out into Camden Bay are more than 40 mi (64 km)
east of Cross Island, and given this distance plus the low-level sound
source of the ice gouge surveys, this will mitigate impact to the
Nuiqsut bowhead whale subsistence harvest. Timing of activities will be
coordinated via the nearest communication and call centers operating in
the Beaufort Sea, presumably in Kaktovik and Deadhorse. As a result of
the timing, location, and lack of an airgun source for the ice gouge
surveys, any effects on the bowhead whale, as a subsistence resource,
will be negligible.
Ice gouge survey activities in the Chukchi Sea will be scheduled to
avoid impact to bowhead whale subsistence harvests that could be
conducted in the Chukchi Sea communities of Wainwright or Point Hope.
Scheduling will be coordinated via the nearest communication and call
center operating in the Chukchi Sea communities.
(2) Beluga Whales
Beluga are not a prevailing subsistence resource in the communities
of Kaktovik, Nuiqsut, or Barrow. Thus, given the location and timing of
site clearance and shallow hazards and ice gouge surveys in the
Beaufort Sea, any such behavioral response by beluga to these
activities would have no significant effect on them as a subsistence
resource.
Belugas are a prevailing subsistence resource in the Chukchi Sea
community of Pt. Lay. The Point Lay beluga hunt is concentrated in the
first two weeks of July (but sometimes continues into August), when
belugas are herded by hunters with boats into Kasegaluk Lagoon and
harvested in shallow waters. Ice gouge survey activities in the Chukchi
Sea will be scheduled to avoid the traditional subsistence beluga hunt
in the community of Pt. Lay. Timing of any ice gouge survey activities
will be coordinated via the nearest communication and call centers
operating in the Chukchi Sea, presumably in Wainwright and Barrow.
(3) Seals
Seals are an important subsistence resource and ringed seals make
up the bulk of the seal harvest of both Kaktovik and Nuiqsut. Seals can
be hunted year-round, but are taken in highest numbers in the summer
months in the Beaufort Sea (MMS 2008). Seal-hunting trips can take
Nuiqsut hunters several miles offshore; however, the majority of seal
hunting takes place closer to shore. The mouth of the Colville River is
considered a productive seal hunting area (AES 2009), as well as the
edge of the sea ice. Lease blocks where site clearance and shallow
hazards surveys will occur are located over 15 mi (24 km) from the
mouth of the Colville River, so there is less chance for impact on
subsistence hunting for seals. Ice gouge surveys in Mary Sachs Entrance
in Camden Bay will be conducted (AES 2009) over 30 miles from the
westernmost extent of seal hunting by Kaktovik hunters (AES 2009). The
remainder of ice gouge lines will be much further offshore than where
Kaktovik seal hunts typically occur which is inside the barrier islands
(AES 2009). It is assumed that effects on subsistence seal harvests
would be negligible given the distances between Shell's proposed site
clearance and shallow hazards and ice gouge surveys and the subsistence
seal hunting areas of Nuiqsut and Kaktovik.
Seals are an important subsistence resource in the Chukchi Sea
community of Wainwright. Ringed seals make up the bulk of the seal
harvest. Most ringed and bearded seals are harvested in the winter or
in the spring (May-July) which is before Shell's ice gouge survey would
commence, but some harvest continues into the open water period.
Hunting that does occur during the open water season generally occurs
within 10 miles of the coastline (AES 2009), while the majority of ice
gouge survey activity will be much further offshore. Timing of
activities will be coordinated via the nearest communication and call
centers operating in the Chukchi Sea, presumably in Wainwright and
Barrow. It is assumed that effects on subsistence seal harvests would
be negligible given the timing and distances between Shell's proposed
ice gouge survey and the subsistence seal hunting area of Wainwright.
All survey activities will be operated in accordance with the
procedures of Shell's Marine Mammal Monitoring and Mitigation Plan
(4MP) that accompanies this program. This potential impact is mitigated
by application of the procedures established in the 4MP and to be
detailed in the POC. Adaptive mitigation measures may be employed
during times of active scouting, whaling, or other subsistence hunting
activities that occur within the traditional subsistence hunting areas
of the potentially affected communities.
Shell states that it will continue its adopted spatial and temporal
operational strategy that, when combined with its community outreach
and engagement program, will provide effective protection to the
bowhead migration and subsistence hunt.
Based on the above analysis, measures described in Shell's POC, the
proposed mitigation and monitoring measures, and the project design,
NMFS has determined that there will not be an unmitigable adverse
impact on subsistence uses from Shell's 2010 open water marine survey
activities in the Beaufort and Chukchi Seas.
Endangered Species Act (ESA)
There are two marine mammal species listed as endangered under the
ESA with confirmed or possible occurrence in the proposed project area:
the bowhead whale and the humpback whale. NMFS' Permits, Conservation
and Education Division consulted with NMFS' Alaska Regional Office
Division of Protected Resources under section 7 of the ESA on the
issuance of an IHA to Shell under section 101(a)(5)(D) of the MMPA for
this activity. A Biological Opinion was issued on July 13, 2010, which
concludes that issuance of an IHA is not likely to jeopardize the
continued existence of the fin, humpback, or bowhead whale. NMFS has
issued an Incidental Take Statement under this Biological Opinion which
contains reasonable and prudent measures with implementing terms and
conditions to minimize the effects of take of listed species.
National Environmental Policy Act (NEPA)
NMFS prepared an EA that includes an analysis of potential
environmental effects associated with NMFS' issuance of an IHA to Shell
to take marine mammals incidental to conducting its marine survey
program in the Beaufort and Chukchi Seas during 2010 open water season.
NMFS has finalized the
[[Page 49758]]
EA and prepared a FONSI for this action. Therefore, preparation of an
EIS is not necessary.
Authorization
As a result of these determinations, NMFS has issued an IHA to
Shell to take marine mammals incidental to its 2010 open water marine
surveys in the Beaufort and Chukchi Seas, Alaska, provided the
previously mentioned mitigation, monitoring, and reporting requirements
are incorporated.
Dated: August 6, 2010.
James H. Lecky,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2010-19950 Filed 8-12-10; 8:45 am]
BILLING CODE 3510-22-P